thanks, the water is 20c maybe 70f. I swam 1km in open water a few times, my form probably goes out the window but it's nice to swim in cool ocean water. my sighting is terrible, and people often comments I don't swim straight at all. i've done no formal training. and no wetsuit is required
my sighting strategy is currently to look foward after breathing, that is 1) breath 2) keep head above water 3) look forward 4) submerge head.
I think since there will over 1000 people swimming, I will just follow the bubbles.