Joe, A few simple rules.
If you did not do it with MHZ dont do it with 2.4. Meaning.. If you did not lay the RX antenna horizontal i the boat with MHZ dont do it with 2.4 either. Just some basics like that.
Then.. a Diversity RX is ALWAYS best.. and they are readily available..
(28) Futaba Diversity RX - YouTube
Futaba Marine team members recommend the use of a 400mm RX antenna. Can you get away with out it.. YES.. but, whatever the case. its best to get the end of the RX antenna as far up away from the water as you can.
Its best to you (as described in the manuals of the systems, to you genuine Futaba Electroncis with your Futaba radio systems.
Its best to use a RX battery that CAN deliver the amperage needed to get it all done. Having not used one.. It looks like Bill Brandt has a great option. MAKE SURE THE BATTER IS 10C OR MORE! NICD,, sure.. NIMH.. eh.. i dont know.. not for me.. LiFe, great choice BUT.. it must be over 10C.. and LiPo.. s.......ure.. sometimes.. if you have the experience and understand what you are dealing with... then sure.
Grim