Wow, that is SO impressive, that you go in the water and use your kickboard if you are scared of water and can't swim! I'm seriously in awe of you right now.
Btw - don't misunderstand my earlier comment. I just meant that I think swimming burns fewer calories if you do it for a shorter time. Obviously it's still a great workout, and if you have stamina, then that's awesome. It is of course also fun! I used to swim competively, but I hardly ever go now. When I go, it feels so wonderful. But when I walk, there are mushrooms, and berries, and nuts to be found, which really take your mind of the idea that you're exercising