10 Best VHF Marine Radios in 2019 Review and Buying Guide

Mayday, mayday! You’ve likely navigated onto this page because you don’t already have a reliable way of communicating while out on the water, and that’s a major problem that you and I are going to fix together! 

In this guide, we’ll have a discussion as to why you need a marine radio, how to use them, what to look for, how they work, and finally, where to snag the best deals on today’s best marine radios.

black marine radio

I’ll briefly touch on some regulations and laws regarding usage, however, it is solely up to you to be familiar with local and international regulations regarding maritime radio communication. 

This topic is one of the more difficult but also imperative topics I’ve written about. Radios can seem quite complex and figuring out what you need to be equipped with and how to properly use them can certainly be a daunting task! Hang on tight and I’ll do my best to take you from beginner to expert in the world of marine radios!

Buying Guide

I’ll be going over some of the most popular handheld and fixed-mounted VHF marine radio units available now. As with all technology, it’s impossible for me to keep up to date with every single new unit and advancement, so if I miss something or something new comes out, kindly let us know in the comments section and I’ll do my best to add it to this list!

Here Are The Best Marine Radios

1. Standard Horizon Explorer GPS GX1700W Class D

Standard Horizon Explorer GPS GX1700W Class D marine radio

Price: Around $215​

My Review: I’m a huge fan of this radio and I think many people agree, especially since its a best seller across several online platforms. At first glance, it may seem better to save a few bucks and go with a slightly cheaper model, but I really think the price is worth it and I’ll do my best to explain why.

First and foremost, the 3” LCD is among the best in the business and provides tons of information with an incredible backlight that is easy to read even in direct sunlight.

I can’t tell you how many of these radios I’ve seen mounted on boats where they’re nearly impossible to read during the day unless you put your face inches away from the display.

DSC capabilities on this radio are also some of the best in the business. The 12 Channel GPS integration is available right up front, making wiring your radio to your GPS unit incredibly easy. The DSC used here is the ITU-R M493, which is a class D VHF that encompasses a separate Channel 70 receiver. This ensures you’re capable of receiving DSC calls even when listening on other channels.

Furthermore, the DSC positional request system is top notch and allows you to make a GPS request or share your GPS data with other vessels with the touch of a button. When wired up to your GPS unit, the DSC position request will be automatically displayed on the GPS chart plotter (if compatible) via 2 NMEA wires. 

These units are RAM3+ compatible, meaning they are capable of being connected to with a RAM3+ remote microphone. This makes communicating through your radio from different portions of your vessel an absolute breeze and has spoiled me so much that I won’t use a VHF radio without this feature. 

Speaking of microphones, this marine radio utilizes the Clearvoice noise reduction system. In a nutshell, this removes background noise like wind, mechanical noise, etc. 

Something I found to be rather adorable was the customizable programming of channel names. You can name each channel which makes remembering their usages very easy. 

Of course, this radio comes equipped with the standard 10 NOAA weather channels which are easily navigated by using the WX key. You’ll also be able to set up customizable weather alerts and audible tones.

Why I like it:

  • This is one of the most feature-rich marine radios on the market today and I believe it’s an excellent value
  • This unit is capable of saving 100 custom GPS waypoints and communicating these directly to your onboard GPS unit
  • Since I am always finding myself on different vessels, it’s nice to be able to move my GPS unit with me. Since this radio makes it so easy to wire the two together, I save a lot of setup time and get to use that time doing what I love instead

2. Uniden UM415 Class D

Uniden UM415 Class D marine radio

Price: Around $290

My Review: Available in both black or white, the UM415 is an excellent value in terms of fixed-mounted marine radios.

I’d recommend anyone with an especially small craft that needs a fixed-mounted radio to buy this radio because of its compact size and easy installation. I think that if you have a large vessel, this radio is still great, but I’d probably opt for something else, such as the Explorer GPS GX1700W.

This radio encompasses several great features such as Triple Watch Plus which allows the monitoring of Channel 16 and Channel 9 plus another custom selected channel all alongside weather alert scanning. Another great notable feature is the Quik Command One-Touch Ch 16/9 Channel selectors on the microphone, making switching to these channels extremely fast and easy to do in a pinch.

This radio is capable of both 1W and 25W transmitting configurations and includes the S.A.M.E weather emergency alert system. It has a front facing full class D DSC button protected by a flip cover. 

Overall, the design is fantastically rugged while maintaining a very slim and compact form factor. The entire unit is exceptionally easy to use and despite its small stature, it’s packed to the brim with features. Even the microphones real-estate wasn’t sparred from cramming quick shortcuts and features onto it!

Why I like it:

  • Although I think the Explorer GPS GX1700W has the best overall display, I really like this display in terms of compact fix mounted radios due to its bright amber glow
  • The targeted SAME weather alert system is very convenient and accurate and includes tide reports
  • This is the leading edge in compact fixed mounted marine radios

3. Cobra MRF45D Class D

Cobra MRF45D Class D marine radio

Price: Around $135

My Review: This is the cheapest option on my list of fixed-mounted marine radios but that doesn’t mean you shouldn’t consider it! This radio is just a simpler and more elegant device, made for the purists and people that want the least amount of bells and whistles in the way of what they need the most, which in this case, is communication.

Of course its totally DSC capable with all the standard DSC goodies such as a quick one-touch distress button located on the front panel and it’ll transmit your communications in either 1W or 25W power configurations.

Furthermore, you’ll get the typical 10 NOAA weather channels with audible storm alerts and the standard international coverage scheme with 3 channel maps. This unit from Cobra utilizes Dual-watch technology that allows you to monitor Channel 16 and another channel of your choosing simultaneously. 

The unit is very compact when it comes to mounted radios and instead of a rugged or technologically advanced design, they went with slim and simple. The unit itself is actually JIS7 waterproof, meaning it’ll withstand a splash here and there.

Why I like it:

  • It’s slim, it’s simple, it’s sleek, and it gets the job done at a very fair price
  • The microphone is exceptional and utilizes noise-canceling technology to ensure your outgoing communications aren’t droned out by the wind or engine noise
  • The LCD, although small, has brilliant illumination and is rather easy to read so long as you’re close to it

4. Standard Horizon HX870

Standard Horizon HX870 marine radio

Price: Around $200

My Review: The HX870 is a class D handheld radio that supersedes the old version, the HX851.

These radios float, making them an excellent choice among kayakers and the like and of course, they’re waterproof, coming with a standard IPX8 waterproof rating. Furthermore, like many handheld VHF radios, these are capable of floating, meaning that if you drop them or you need both of your hands when in the water, you can just set it next to you and it won’t find its way to the bottom of the ocean!

Speaking of being in the water, the HX870 has an automatic water detection module that will, upon being in contact with water, flip on its emergency strobe light function which is surprisingly bright and especially perfect for being lost at sea at night. 

The Standard Horizon HX870 is equipped with DSC and features a powerful WAAS GPS receiver with 66 Channel integration. This is all interfaceable through the oversized full dot-matrix LCD screen that measures roughly 2.3” diagonally. These screens are used for their incredible detail but extremely low cost to battery life. 

Some VHF radios have a blue or orange background, which many people seem to enjoy, however, these monochrome screens tend to save a lot of battery so I think it’s a fair tradeoff. Although the screen lacks color, the keypad does utilize a faint red illumination to ensure accurate and easy usage in the dark. 

This handheld allows you to choose to transmit power levels at 1W, 2W, or 6W, which is incredibly useful for both short to mid-range communications. Battery life is pretty good on this unit too with many reports in unison agreeing that it is one of the longest lasting handheld devices on the market. 

For the price, this is probably the best bang for your buck and overall, I’d say this is the best handheld VHF radio for the average joe. There are a few radios out there that include better features or have some ease-of-use tidbits that are useful, but this radio seems to be the most durable and dependable with everything you need.

Why I like it:

  • IPX8 waterproof rating and built-in automatic emergency strobe light
  • WAAS GPS implementation with 66 Channel integration with customizable waypoints
  • Incredible, nearly unrivaled 10-hour battery life due to a hefty 1800mAH Li-Ion Battery and 12VDC 3hr quick charger

5. Icom IC-M73

Icom IC-M73
Price: Around $185
 
My Review: This radio feels and behaves a lot like a Walkie Talkie, which is nice since most of us are probably familiar with carrying one of those around with us at some point.
 
The design feels nice and ergonomic, they didn’t go overboard in engineering and attempt to change the game and instead, they remained simple and sweet, which I can appreciate.

Something I think is really notable with this device is how insanely loud it is. Out of all of the handheld units on this list, this one is by far the loudest and provides the best overall audio experience. Icom achieves this incredible volume level by using a BTL (bridge-tied load) amplifier, which they claim doubles the audio. I’m not sure it’s double as loud as the other units, but it’s certainly louder. 

The IC-M73 can be operated at 6W of transmitting power, which seems to be the new industry over the older, more traditional 5W maximum. Simply put, that one extra watt doesn’t really seem to help in range, despite the description of the product claiming so, but it does help your audio traffic punch through busy channels and white noise. 

Something else I really like about this particular radio is the dual/tri-watch function that allows you to monitor several channels, such as channel 16 simultaneously with other channels. 

Most handheld VHF radios have a floatation device but please do not assume they all do, as this one certainly does not. If you drop this into the water, it’s most likely going to visit Davy Jones, so be extra careful! It is waterproof, though, so hey, if you have some scuba gear you might be able to retrieve it! 

Last but not least, battery life is rated at 18 hours, which I believe is an overstatement. It’s probably closer to 10-12 hours, which is still pretty good, especially when it has to power that onboard audio amplifier.

Why I like it:

  • 700 mW Audio amplifier sets this handheld VHF radio apart from the others with insane audio volume
  • The LCD screen is incredibly bright, one of my personal favorites in contrast to other handheld radios
  • The design is simple and ergonomic and seems to weigh less than most radios I've had experience with

6. Standard Horizon HX300

Standard Horizon HX300 marine radio
Price: Around $115
 
My Review: We’ve talked about a similar model to this, the HX870 and although I do recommend the HX870 to most people, I think the HX300 still has a rightful place depending on your needs.
 
First off, it’s cheaper, so there’s that. Second, it’s far more compact and lightweight than the larger Standard Horizon models. This little thing can fit in your pocket almost like an old Nokia cellphone.

Its transmitting power is capped at 5W, which does put it at a slight disadvantage to the new 6W models that are flooding the market, however, the difference is minuscule and to me, it’s a fair tradeoff for portability and weight. Furthermore, its equipped with a very respectable 1650mAH 3.7V Lithium-ion battery that should get you in the ballpark of 10 hours of usage. 

This unit is rated at IPX8 in terms of waterproofing and does have a floatation device installed inside, ensuring you don’t lose it if you drop it or find yourself taking a surprise dip in the water.

This radio is equipped with NOAA weather channels, customizable weather alerts, and utilizes all of the traditional US and Canadian channels. 

The screen is a very tiny monochrome LCD with orange key illumination built it. Just like the HX870, this radio does have a water-activated strobe beacon.

I recommend this to anyone on a budget or looking for something extremely small. If you’re venturing out in a large vessel, you should look to a mounted VHF radio or something with more features, like the HX870, but if you’re taking out a kayak or something similar, this unit is fantastic and will certainly save a little space.

Why I like it:

  • Although it comes with a USB charger and cord, you can plug it into any USB port to charge and receive a full charge in roughly 3 hours
  • This is one of the most compact units on the market that sacrifices very little to achieve its tiny form factor
  • The 600mW audio speaker is pretty good, probably the best among compact units and far better than what I would have guessed it would come with

7. Cobra MRHH350FLT

Cobra MRHH350FLT marine radio

Price: Around $115

My Review: This unit finds itself in the middle of both budget and excellence, so it’s hard to recommend it directly to a specific crowd of people, however, if you’re a big Cobra fan already, it’s a pretty good buy and significantly better than the cheaper Cobra radios.

The power transmission levels available are 1, 3, and 6W which is on par with some of the best handheld devices on the market today and will safely cover at least 3 miles with ease. It comes equipped with tri-watch, which essentially means it’ll scan three different channels simultaneously.

You’ll get the typical 10 NOAA weather channels in addition to all of the standard US and Canadian channels. If there is a severe weather alert, this device will play a loud tone alerting you to possible dangerous changes in the weather.

Its waterproofing is pretty good and will allow safe submersion at 3’ for up to 30 minutes due to its JIS7 / IPX7 waterproof ratings. Speaking of water, this unit will float, ensuring you’ve got a second chance to scoop it up if you accidentally drop it overboard. For just a bit more money, you can find units rated at IPX8, which I think is certainly worth the money but if you’re a careful person, IPX7 certainly isn’t bad. 

Like I said before, I’m not entirely sure who would benefit greatly from this device, other than if you’re already a fan of Cobra products. Don’t get me wrong, it’s an excellent radio, but I think if you’ve got a full sized vessel that you’d want something a bit more feature rich and if you’re going out on a kayak that you’d likely want something a tad smaller. This unit kind of fits in an odd in between, but hey, if that’s what you’re looking for then I’d say this is a safe investment.

Why I like it:

  • It’s a decent middle ground between feature-rich, cost, and portability
  • For being what I’d consider a full-size handheld radio, it is certainly lightweight and feels great clipped onto a PFD
  • Utilizes a noise-canceling microphone and water purging speaker to ensure excellent audio quality, even when floating in the water

8. Uniden MHS75 2-Way VHF Radio

Uniden MHS75 2-Way VHF Radio

Price: Around $85

My Review: This is probably my “best bang for the buck” budget radio due to the excellent array of useful features with a price tag under a hundred bucks. Uniden is a very responsible and trustable brand that I have tons of experience with across many different devices and rarely have I ever been disappointed by them.

First off, this bad boy comes with an IPX8 waterproof rating, which is great because units in this price range typically have IPX7 or lower. Past just the excellent waterproofing, though, is just an overall fantastically rugged design.

It’s all aluminum and it just feels excellent in every way. If you were to hand this to me before I knew what it costed, I’d have guessed it would have been in the $120 area.  

Finally, we find out why it’s so cheap! Unlike the better handheld radios on this list, this one has a maximum transmitting power level of 5W, which isn’t bad but I really would have liked to see a 6W option available. Something odd you’ll notice is the 2.5W power setting, which is usually a 3W option instead on most handheld VHF radios. 

This radio has the tri-watch feature, which means it’ll monitor multiple channels including Channel 16 and Channel 9 with another channel of your choosing. This radio is usable on all of the standard American and Canadien channels. But wait, there’s more. There’s also a quad-watch function as well as a dual-watch. 

Just like some of the more expensive radio’s on this list, the MHS75 allows for the standard 10 NOAA weather channels and NOAA weather alerts with very loud audible alarms when the weather changes for the worst. 

Battery life is pretty good, coming in at roughly 12 hours on a single charge. The unit comes with a DC cigarette lighter charger and the radio will audibly alert you when the batteries are dangerously low. 

This is probably one of the best starter radios available today. If you’re on the fence about getting a radio or you think you’d only use it a few times a year, you probably wouldn’t want to spend over a hundred dollars and lucky for you, you don’t have to. This radio offers all the standard features and packs them into a very rugged and compact aluminum shell that I believe is an excellent deal. To boot, you’ll also get a lanyard and belt clip thrown in on the deal, not too shabby!

Why I like it:

  • The LCD screen on this unit seems to be a respectable size among VHF radios and is one of the easiest to read in direct sunlight
  • IPX8 waterproofing offers excellent peace of mind and is not something you normally see at this price point
  • The overall look and feel of the radio is just simply brilliant with a very elegant but sturdy aluminum casing and an SMA rubberized antenna that all feels indestructible

9. Uniden Atlantis 150

Uniden Atlantis 150 marine radio

Price: Around $95

My Review: The Atlantis is the cheapest IPX8 waterproof marine radio I’d ever recommend to anyone and although it’s cheap, it’s certainly not horrible. Of course, if you’re a radio enthusiast you probably won’t have much respect for this unit but if you’re just getting started or you need a radio to use just once or twice a year, this is probably a great place to start.

The transmitting power is excellent despite this unit being so cheap! I was actually surprised to find a unit at this price point that had a 6W transmitting power capability.

Furthermore, you’ll have the option to switch it to 1W and 2.5W as well. Now, I will say that this unit isn’t really meant to operate on 6W. It’s got a power boost key that is to be used only when 2.5W isn’t quite cutting it. Using the 6W power boost will greatly diminish the already not so great battery life. 

You’ll get the typical 10 NOAA weather channels as well as all USA and CA marine channels which is all navigatable by the backlit LCD screen. This unit allows dual 16 and 9 Channel monitoring. 

The battery life is really my only gripe here. The website says 10 hours but to me, it doesn’t seem to quite reach what other 10-hour capable units do and like I said, using the 6W power boost does wreck battery life rather quickly. 

Not considering the price, this radio is pretty meh. Considering price, though, I’d say it’s a pretty good deal and contains most of what the average person would need.

Why I like it:

  • It’s an excellent value, especially with its IPX8 waterproofing and 6W power boost capabilities
  • The backlit CD display is one of my favorites, despite it being one of the cheaper units I’ve reviewed
  • Weather alert watch more will mute radio chatter while attempting to monitor your present weather channels

10. Cobra Electronics MRHH125

Cobra Electronics MRHH125 marine radio

Price: Around $60

My Review: Simply put, this is one of the cheapest VHF radios on the market that is actually worth buying, and I say that sparingly. I would not rely on this radio to save my life, but more so as a backup or entry level device to get started on a budget. 

It’s only like $60, so I wasn’t expecting too much. Unlike most handheld VHF radios, the transmitting power falls short with a maximum power output of 3W. It’ll get the job done, but don’t expect to reach vessels with excellent clarity that you can’t see with the naked eye.

This radio is powered by 5 AAA and does support recharging, which is nice because you can always throw in regular batteries if needed or save money by recharging the ones it comes with Again, I’d say this is more like a backup radio in case you lose or damage your primarily handheld VHF as you’ll only get roughly seven hours of battery life per charge, which is quite a bit less than most other devices on this list. 

The display is a 1.6” orange/red backlit LCD that is fairly easy to navigate. The keys are not backlit but they are decently large and easy to use. 

This unit does only weigh 6.5 ounces, putting it at the lightest unit on the list by a hefty margin, so perhaps it would be nice to have when kayaking or taking a stroll when docked since you can slide it into any regular pant pocket with ease. 

You’ll get all the standard US and Canadian channels with 10 NOAA channels as well. This device has three different scan modes, all-channel, dual-scan, and memory scan. 

This radio is not waterproof and will not survive full submersion despite what some sellers online claim. With that said, it is technically JIS4 certified, which means it should repel a splash with ease, however, I have personally not tested its splash proofing capabilities so beware!

Why I like it:

  • It’s a great budget device and nothing cheaper even comes close to comparing
  • The AAA battery configuration may be favorable depending on your situation and lends itself to roughly seven hours of usage
  • This is a great budget backup that I’d highly recommend someone with a better radio to invest in, just in case!

Why Every Watercraft Captain Should Have a Marine Radio

Safety first, right? Right! Communication has been the deciding factor of life and death in countless scenarios since the dawn of humanity and although many things have changed over the years, having a direct line to other humans to call for help has remained relatively the same. 

Every sob story of a tragedy out on the water usually begins with a lack of preparation and disrespect to the environment. There is a myriad of threats that simply just don’t seem like they could ever happen to you. You’ll be fine, right? You know how to navigate rogue waves, you know your boat, you know how to repair things, you’re a strong swimmer, right? 

Unfortunately, we lose far too many people that are “fully capable” of taking care of themselves each and every year. Having a radio onboard isn’t a sign of weakness, it isn’t a sign of fear, it isn’t a sign of dependency. It’s a sign of intelligence. 

Marine radios give us the ability to communicate with the Coast Guard and also other vessels if needed. The Coast Guard has a very expensive and very expansive network of communications towers around the world that grants anyone with radio access to help when they need it. 

Furthermore, having a radio allows you to pick up on distress calls and come to the aid of a fellow fisherman. Accidents happen and sometimes some quick heroics are necessary, even from you! 

Using a marine radio is also handy in communicating with harbors, docks, locks, bridges, marinas, etc. If you’re sailing international waters, you’ll need a radio to communicate with the local coast guard and law enforcement, especially if you plan to dock in a foreign country. 

As a final note to consider, most marine radios are fully capable of receiving weather broadcast reports when/if they are in the range of on entity broadcasting such information. These reports can also provide vital warnings such as natural disasters or conflict. 

Marine Radios Explained

Before we get to the nitty gritty intricacies of how they work, we must first define the two types of marine radios available to you. 

Handheld: Pretty self-explanatory, these are radios that look a lot like a walkie talkie and are meant to be held in your hand, clipped on your belt, or kept in your bag in case of emergency. Having portability and a small form factor does come at a cost, though. These usually have less range and fewer options than a fixed radio but are especially useful if you plan to use multiple different watercraft. 

Fixed Mount: These are radios that you would install permanently somewhere easily accessible in your watercraft. These usually come with a detachable corded radio and the radio unit itself sits on a swivel. Fixed radios typically have the option to be used with an extended antenna, giving you further broadcasting range. 

A marine radio is classified as a Very High Frequency (VHF) radio, which essentially means it has access to an all-inclusive radio frequency band between 156MHZ and 174MHz. This range of frequencies is regarded as the maritime mobile band and is an international idea, meaning the same rules apply despite where you are in the world. 

How to Utilize Marine Radio Technology

VHF radios operate on an international standard and have very distinct rules and regulations as to how they are used in communication. Channel 16 (156.8 MHz) is the international distress and communications channel. 

Channel 16 can be used in a wide variety of applications, most of which are used to establish a baseline of communication that then moves to a more private channel. For the most part, channel 16 is used for urgent communication in which one or more parties are in distress, requiring the assistance of the Coast Guard and/or nearby vessels. 

International regulations require all vessels to achieve a constant state of “radio watchkeeping”, which essentially means they are open to communication and monitor channel 16 at all times while sailing. This may only be circumnavigated when actively communicating on another channel. 

It is standard to move communication off of channel 16 as soon as possible, most likely within the initial point of communication to leave the channel clear for other users who may also be in distress.  

Sending a Distress Signal

When an emergency arises that is life-threatening, you have two options in order to ask for help from other vessels and the Coast Guard. First, if you have a DSC enabled radio on hand, activating the automatic distress transmission system would be the first thing you can do. 

If you receive no response or do not have a DSC enabled device, using Channel 16 to broadcast your distress is your best option. The proper procedure for broadcasting such an event on Channel 16 is as follows: Call out “Mayday” three times followed by your ships name, your coordinates, and the issue at hand. 

A distress signal would sound like this: “Mayday Mayday Mayday, Seastar. Position 20°35′ North and 77°51′ West. Our vessel is sinking”.This entire message can be repeated three times. If someone is severely injured, including brief information about the injury may help rescuers be prepared for treatment once they arrive. Furthermore, including information about how many people are on board may also be imperative to rescue efforts, especially if people are overboard or the vessel is sinking as it will allow the responding crews to continue searching for people until they find everyone. 

When a distress signal is sent via DSC, the device will include the ships MMSI number and attempt to include coordinates and other GPS information if possible. You have to connect your GPS and DSC devices and set them up accordingly for your DSC to automatically broadcast this information. Distress signals can be sent in both single-frequency and multi-frequency configurations.

A single-frequency distress signal is issued across a single band. The system will then await a response for a maximum of four minutes before issuing another distress signal. This will be repeated five times until switching to a multi-frequency configuration.

A multi-frequency distress signal is sent on all medium and high frequencies in an attempt to receive any and all responses. Since this uses your return antenna for each sending without a time lapse between transmissions, you will be unable to receive transmission while attempting a multi-frequency distress signal. 

Distress signals can come in both a specific designation and a general or non designated transmission. A designated distress signal will send out information pertaining to one of ten pre-defined groupings with the aim of identifying the source of distress. 

Designated distress signals are as follows: Man overboard, violent incursion and/or piracy, vessel disabled, punctured or sinking, listing, fire or explosion, flooding, collision, grounding, and abandoning ship. 

A vessel who receives a distress signal that is outside the range of a coast station is required to relay the distress alert to the utmost level of their capabilities. When a coast station receives a DSC distress alert, the station will immediately send an acknowledgment and the sending unit will both cease repeating and tune in on the designated channel for the distress message to be sent. 

Digital Selective Calling

Seagoing vessels that utilize a permanently mounted radio are now required by international regulation to be equipped with Digital Selective Calling (DSC). DSC can be utilized across medium or high-frequency channels and is a core integration of the Global Maritime Distress Safety Program (GMDSS). All fixed-mount VHS radios manufactured since 1999 come with DSC.

DSC is essentially an automatic distress signal that attempts to alert anyone and every one possible with information regarding your problem. 

By using a narrower but more powerful band, DSC eliminates receiver squelch and has a 25% increase in speed and range over traditional analog signals. DSC requests contain the ships Maritime Mobile Service Identity (MMSI) and may also contain a ships GPS location. 

DSC greatly enhances the safety features of a marine radio by allowing a single push button distress signal to be sent out immediately, over great distances, that contains vital information for emergency response units to track, locate, and communicate with the vessel in need. 

Many ships equipped with DSC use a separate VHF radio and MF/HF DSC controllers that allows a dedicated reviewer to monitor Channel 70. This way, your primary receiver is always in use for regular communications while your DSC dedicated receiver is always monitoring and ready to call for help. 

Marine Mobile Service Identity Number

The Maritime Mobile Service Identity (MMSI) number is a 9 digit number unique to your vessel that is assigned to your radios DSC system. This basically attaches information about you and your vessel to a profile that the Coast Guard can easily access in case of an emergency, greatly increasing the effectiveness of help during distress. 

You can register for your personal MMSI here. It’ll cost about $25. 

Setting Squelch 

A telecommunications squelch is essentially a noise gate that regulates and suppresses what your radio will and will not pick up. This ensures the radio remains silent and usable when not receiving an actual transmission, effectively reducing channel noise. 

An open channel without suppression will create a white noise type transmission that is constant and unnecessary, not to mention annoying and distracting. 

To properly set squelch, turn the SQL knob until you faintly hear a white noise sound, then back it off ever so slightly. Setting your squelch too low may result in lower performance of the receiver, meaning weak transmissions from far away may not be picked up on your radio. 

False Mayday Calls

Yes, using a marine radio to call out a false distress signal is illegal and punishable by up to six years imprisonment and fines up to $5000 USD in civil court and fines up to $250,000 USD in criminal court. Simply put, do not call for help unless your distress is legitimate. 

On top of all of that, you may be required to reimburse the Coast Guard for the time and assets used to respond to your false call. If you’re curious how much this may cost a criminal, you can check out this website for further information. 

Radio Etiquette

Using a VHF radio comes with a certain level of responsibility and communicative skill set. Keeping messages short but informational is actually much more difficult than most people realize. Oversharing details on vital channels not only bugs other nearby vessels but could impede their ability to communicate and even issue a distress signal.

The proper way to address a vessel is by beginning the transmission on channel 16 (when there is no other radio chatter) with the name of the boat you wish to communicate with followed by your boat name like this: “Seastar Seastar. Galileo. Over”. 

To respond: “Galileo, this is Seastar”. Proper radio etiquette mandates that you only retry your acknowledgment after a full two minutes have passed with no response. Furthermore, you are permitted a maximum of three attempts to get the vessels attention with the 2-minute intervals and after that, you should wait a minimum of 15 minutes before making another attempt. 

Once the vessel responds, a channel designation should be given in an attempt to move from channel 16 to a non-commercial ship-to-ship communication channel. These are channels 68, 69, 71, 72, and 78A. It may be tempting to call these out as “Sixty-eight”, but its actually proper to communicate them as each number individually, like “six-eight” to avoid confusion. 

Once you have tuned in to the communication channel, you would once again acknowledge the other vessel to ensure you’re both on the correct channel and then commence with your conversation. 

Remember, anyone with a VHF radio in range can follow your communication and listen in on your conversation so keep it clean and respectful and be mindful of the details you share. 

Always ending your conversation in “out” allows anyone else awaiting the use of that channel the opportunity to essentially claim it for their communication purposes. 

If leaving channel 16 lands you on a communication channel already occupied by other vessels communicating, you can either wait for the “out” signal of the vessels occupying that channel or you can resort back to channel 16 and designate another communication channel for you and your vessel of interest to attempt. 

Never attempt to communicate other than to “call” another vessel or send a distress signal on channel 16. Channel 9 is an alternative channel to channel 16 designating for calling. 

Technically, profanity over the air is illegal so watch your language. If you can’t say it in a high school classroom, you can’t say it on a VHF radio, even if you think you and the vessel you’re communicating with are on a channel alone. 

Transmission Power and Antennas

Transmission power dictates how far you can send and receive radio transmissions. This is measured in wattage and is usually a variable setting located on the front of your radio. Most fixed-mount VHF radios are capable of operating from 1 to 25 watts and handheld units are generally capable of up to 5 watts. 

Choosing a power level is basically related to how far your transmissions need to travel. If you’re communicating with a vessel that is nearby, perhaps only 1 watt is necessary. This ensures that your communications are not broadcasted far out into the sea where other vessels will unnecessarily hear them. If you’re making a distress call, you’d likely want to use the maximum power output of your device to reach as many vessels as possible. 

Keep in mind that the quality and height of the antenna will be the number one attribute of effective range. The further your antenna can “see”, the more range your radio will have regardless of the wattage it is set to. 

Higher power levels may help your radio transmission navigate radio noise and impeding traffic. 

For a typical adult standing on the deck of the boat, the viewable distance to the horizon is roughly three miles. Since VHF radios work based on a line of sight and fail to transmit to receivers without a line of sight, three miles will likely be your limit, unless you have a tall antenna perched up high aboard your vessel. The higher the antenna, the further out it is capable of reaching. 

I won’t go too far into detail with antennas because I feel like that’s a topic for another guide all on its own, but as a general rule of thumb, the taller the antenna, the more coverage you will have. Make an investment into a nice VHF radio is a fantastic choice, pretty much a necessity, but if you don’t have a tall antenna, its range will be severely crippled. 

Not having an extended antenna doesn’t always mean you’ll be capped at the 3-mile limit, though. If the vessel you’re attempting to contact is outside of 3 miles, but has a 15ft tall antenna, you’ll likely still be able to communicate with that vessel since the line of sight will still be present. Remember, it’s less about the total range and more about seeing over the curvature of the Earth. 

Some people like to mount their antennas at an angle. This is called a “canted mount” or “raked mount”. This is also called a silly waste of potential performance. Why? Because the higher your antenna, the better its performance, period. 

The higher in elevation the end of the antenna that sticks up into the air and allows for more oversight into the distance, the better your range will be. A canted antenna will only have the performance of how tall it is from the surface of the water, no matter how long the actual antenna is. Straight up and down is the best way to mount an antenna and if you really want to squeeze every ounce of range out of it, you’ll mount it on the highest point of your boat.

Check out this website for Coast Guard VHF coverage maps.

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