well the ply was backed with balsa in some places and the damp has got in the balsa and thats the bit that delaminated rather than the atually ply itself, the ply is actually very good. expensive too.
Ive stripped the esc and lipo apart, ive cleaned them up. the lipo stll shows nearly 4 volts per cell so im hopeful about that. the brushless esc was green and gunky but ive cleaned that up tested it and it still works but forward only now. it doesnt matter though because on surface drive it didnt work in reverse anyway. motor is fine too.
In all honesty ive managed to salvage 90 percent of it with a bit of fettling all i need is some new battery connectors, new a propshaft coupling, bit more ply and ill build another boat. I bought a traxxas to tamiya extension cut the tamiya off and soldered the the traxxas end to the lipo. i took extra care in soldering my bit but didnt check the connection that came with the connector and it was that that failed. all this for a £1.20 peice of wire!!
its funny really because the corrosive damage was not caused by water from the lake, the inside of the boat was just damp. all electricals were sealed in balloons it was the build up of condensation and cold inside the balloons that got them wet.