On a regular basis, I stand in mud/water up to my knees welding conductor pipes and well heads under drilling rigs. I wear rubber boots and have no problem getting zapped......unless my gloves get wet.....then I switch to rubber gloves. Sparkee
this is not neccesarily an underwater weld but if you followed some of the same rules you would be ok. use DC striaght polarity electrode negative (and a compatable rod 6010 or 6011 should work alright) and wear rubber gloves make sure the wadders don't have any holes in them. I always found that those half in and half out of the water welds were the hardest to make but not impossible.