We, erm, did set out with the best of intentions but, erm, the temptation of the shallow pools kinda got the better of us... One of those "I'm sure it will be fine......" moments. Lesson learnt - no amount of WD40 and similar seems to have stopped the rust. I think I'm actually going to have to use some rust treatment on the metalwork if I get the electrics back running. It's an FTX so thankfully not an expensive mistake.