Whatever you buy, be suspicious of its waterproof claim and use a waterproof radio case that still lets you operate it. Some member have found to their cost that after a bit of use some part of the radio will leak, usually with fatal results. Good brands e.g. Standard-Horizon, ICOM, Cobra and others. Make sure it fits in a pfd pocket wit a case on it. It is best select a radio that accepts alkaline batteries, of which you can carry many extras, rather than relying on a rechargeable battery when there is nowhere to recharge it on a multi-day trip. Both are nice to have. Most paddlers leave their radios turned off most of the time to conserve battery power (and to avoid annoying radio chatter).