RE: Which radio for boat?
is your JR 9303 the 2.4Ghz system?
there is an advisory that came out in 2008 for the 9303 2.4, an electrical problem. if your radio is newer than 08 you should be good.
as for a good radio at good price, you have the Futaba 3PM 2.4Ghz FASST system that works great.
Spektrum also has a new radio with the MR3000 (Marine) receiver 2.4Ghz that is suppose to be working good which solved the problems that they had before in boats.
3 channel is fine and does not cost more, even if you don't use it right away, if the time comes that you do need it than you have it.