Lets see, today the sea-surface temp here was 46 F and the air is in the low 40's. Bottom fishing opens up on Mar 10, but its still too cold for me to don a 3mm farmer john wetsuit with extra layers, and go kayak fishing here along the Jetties. I like everything to be above 50 F, preferably mid-50s, but I may venture forth in my Tarpon on calmer days, despite sub-52 degree water, with the determination to absolutely avoid capsizing. That's not hard. I just don't look forward to frozen toes. And that's with 6mm booties. I'm thinking of slipping some toe warmers inside my booties. There's not much extra room, since they fit right without anything in the toe space. I'll probably just wait. With temps above 52 or so, my toes don't seem to get frozen. Another reason I like to wait until everything warms up a bit more is that I believe that the fish are more active then.