It may be a transmitter/receiver problem or it may be in your drive setup that rears its ugly head once your on the water and your motor is under load. I had a similar problem with a twin motor setup which was fine out of the water but after 10 mins in the water I would lose drive to one or both props or one would slow down and just go round in circles (very embarrassing). I had no problem with radio setup so it had to be in the drive chain. I ended up changing both motors for ones with more armature poles, higher torque output and a different gear ratio. it also highlighted a problem with my first choice of battery which quite frankly were pants and used to produce similar symptoms as you describe. I now use Lipo power packs, they do have disadvantages but you can not knock the power to weight ratio. The main problem I was having appeared to be down to the 3 pole motors that were fine until they were under load, this caused the motors to overheat which in turn increases the current drain on the battery's, the net result is the motor starts to arch across the commutator and effectively becomes a dead short which in turn shuts down your ESC's or drains your battery's very quickly. As you probably know if this was to happen with Lipo's there would be no need for a smoke generator! Of course this only applies to brushed motors if you are using a brush-less motor then it will probably not help you.

thanks for thatDavid will try it out and let you know👍

hi,
it sounds like you have the receiver to low in your boat, try lifting it higher up above the water line if possible. as I said before submarines don't work very well on 2.4 ghz because they work below water level try it and let us no if it works. its a common problem with 2.4ghz unless you put receiver above water line. a few people I have spoken to have gone back to 27mhz or 40mhz. also you will notice the antenna is only short try putting this above as well.

david

Hi David its a Turnigy TGY16 2.4ghz if that helps thanks for the prompt reply😁

hi, what type of transmitter are you using eg, 40mhz, 27 MHz, our 2.4ghz. you can find that 2.4mhz, if the receiver is below the water line reception can be very poor, i no the submarine guys can only use 27mhz because they go below the water. let us no your set up it makes helping you a lot easyer👍

david