I read an article in Stand Up Paddle mag recently, Confessions of a kayaker. It struck a cord.
I've been doing a fair bit of SUP lately, mostly on the river and canal but a bit in the surf and a trip down the River Dart over the winter.
If you want to check it out then you can hire boards at A.S Watersports really cheaply, get some info and they can arrange some tuition for you as well.
Thumb-SUP. Don't forget your helmet and pfd for white water.
Sunset SUP session.
Gulf of Morbian, Brittany, France.