RE: Vantex Bat Power 1300 Rtr W/26cc Petrol BUY OR NOT TO BUY
I think if you went for a cheap chinese one, and ran it in the sea (salt water) you could find yourself spending time, fixing it and upgrading it with decent parts. Time that could be spent putting together a decent one.
I bought a decent second hand, well built Sigma 51 with a tuned Zenoah in it ready to run off ebay (other then receiver and batt) and it got me on the water straight away and is decent quality kit. This was for the same money you are looking at spending, but you need to be patient for something to come up that you want.
There are brands with good reputations, plenty of info on them on this forum but to get one to the UK you are looking at big money.