Icom or Standard Horizon are both decent makes. I've got a Standard Horizon HX280e on the RIB. Good battery and it holds it charge very well. Very solid lump of a radio as well, waterproof but I'm not sure it floats (it's on a lanyard on my lifejacket so not too bothered). I think the floaty model is about an extra 20 quid. If you go for a Standard Horizon model then watch the cheapo Ebay deals, the European versions have an "e" suffix, the Yank versions have an "s". IIRC it's not a huge difference though, charger and a few channel mappings I'd guess.
Plenty of cheapo handhelds about like Cobra but they don't have a reputation for being long lasting.
I've got the Icom M31 - predecessor to the M33. Waterproof to about 1m (so no problem hosing off with the rest of my kit), rechargeable etc. Can be found second hand for less than £100 - this has always been my preference compared to a 'new' handset from another brand - in many cases handhelds get very little use as backups to main transceivers on boats.