Waterproof Two Way Radio Recommendations?


I need some help in choosing a two-way radio. It will be used in the ocean on a paddle board to contact people back on shore and at the surf shop. We prefer the look of the Motorola RDU4100 (commercial/professional look) and we’ve been eyeing the Motorola T600 and the Uniden GMR5089-2CKHS but are open to other recommendations. We need it to be waterproof and to float. Please let us know what you guys can find!


Then surely you should be looking at proper Marine band radios - which are made for exactly this kind of thing. There are offerings from most of the usual brands, and many look kind of ‘nautical’, most are pretty professional looking. Doing it properly also means you can use them for emergency comms too - after all, being able to switch to channel 16 and call the coastguard is pretty important?

There are waterproof models available that float. However, business radios such as the Motorola RDU4100 are not designed or intended for marine use. You need a marine radio. Icom, Cobra, and Uniden are all recognized brand names with a full line of marine radios. For more information about marine radios, here are a few resources.

TWRS-16 - An Introduction to Marine Radios

Getting Started with Marine Radios

Types of Two Way Radios

It says that marine radios can NOT be used on land. One radio will be on land(shore) while the other will be used on the water…

For ship-to-shore communications you would need to set up a Coast station.

I’m now in between the Cobra HH450 and the Motorola T600. Is the Cobra worth the price difference?

Except it won’t be ship to shore, it will be kayaker, paddle boarder etc. to some one on shore. No more than 2 miles.

It isn’t about type of vessel or flotation device, it’s about location. It could be an inner tube or raft. Technically, it is still considered ship-to-shore.

The usual decider, well at least here in the UK is based on the land user being what they term a fixed station. This allows land use to users with portable radios, and to mobile, vehicle based equipment - Indeed, one of the users is the coastguard. Coastal stations are the fixed location ones, and the licence here is actually quite expensive, however portable radios are commonly found in marinas ports and other locations and they are NOT coastal stations, and here are often tagged with a ‘portable’ or ‘mobile’ callsign. It’s a little awkward paperwork wise here because licences usually link to vessels, but clearly jet skis, tenders for larger craft and surf boarders can all have marine radios. The only requirement here though would be that the radio users all have a short range radio certificate, that requires some training and a test. Ironically, while I have a licence to be able to use a marine radio for testing and demonstrations, I personally don’t have the certificate, so I shouldn’t actually speak on the radio. However, for me to fit a radio to this building and use it, I would be a shore station, with the responsibilities and cost.