C of G and vaqueroaero both make a good point about having a plan.
I always thought my plan would be to do an into-wind auto, regardless of the circumstances. This is one of the reasons for my post as I didn't do this. My boss says one should go to bed at night dreaming of what you would do in certain situations. In principle I agree wholeheartedly, however, I also believe that one cannot account for every situation as things tend to vary.
In this case, had the wind been stronger, or had there been a boat handy, or had I been on my own without anyone else to worry about I wouldn't have done things the same way and would undoubtedly have made a left turn into wind.
As I remarked to SASless, things do happen very quickly and there are a lot of things to do/consider. My actions at the time were, in hindsight, not what I thought I would have done, however a quick decision had to be made and I took what I (rightly or wrongly) believed to be the correct one given the set of circumstances. Once the decision has been made, don't start changing it.
In the final event, there were no injuries and the outcome was as good as I could have hoped for. Impact forces were so small that there was no damage except for some crumpling of the belly panels, a small dent on one tail rotor blade, a broken tail rotor driveshaft and a couple of damaged MR blades. Forward speed must have been virtually nil as nothing around the engine (fan scroll etc) has been pushed back and the mounts and firewall haven't suffered at all.
The only thing I was worried about immediately after the event was that I had somehow mis-read the situation, that drive to the rotor system might actually have still been there and that I had put a perfectly flyable helicopter into the drink. You know, the usual doubts one has. My fears were put to rest when it was salvaged and the obvious cause was discovered.