I've never been a swimmer of any kind, especially in salt water (bad memories of being dumped in the surf as a kid!) but started with some prodding a bit over a year ago. I swim breast-stroke only, don't like freestyle (the Aussie crawl!) as water gets in my ears. And I feel that I'm getting a more complete movement as well. I generally do 800m, occasionally I can muster up a km.
I haven't measured my cardio-vascular fitness (tsk) but it's helped me lose weight and get a few long-lost muscles back!
That is beautiful water you have there John. It looks like fresh water comes in every time the wave comes in. 
You get an occasional wave at high tide, but this one's fairly protected. It's also the only one with lanes, so it's a good exercise pool.
Some of the other pools nearby can't even be reached at high tide! (The satelite pic of that one is low tide - at high tide the reef is completely covered.)
