I did something similar a year ago for my fisheye side challenge but decided to try again but with processing a bit different. I started out with HDR but then decided to try Fractalius, and that did the trick, I got the look I wanted. I used a b&w filter and blended in hard light on top of a regular layer
I love the curve of the fish eye. This is so nostalgic for me. Those old life guard stands always make me think of my Dad who was a lifeguard in Huntington Beach, CA in the 40's.
The clouds look super cool. I generally don't think of a b&w when the sky is so crisp and clear (and probably blue as can be) but this really came out nice.