I'm an experienced sea kayaker - what should I do to have a go?

As an experienced sea kayaker you have a number of key skills that will be directly transferrable to the wildwater racing boat. It should feel pretty familiar in terms of how to steer the boat, probably just a bit more unstable than your sea kayak.

Find a local club, and have a go in a wildwater boat on some easy water to see how you like it, you can of course always take it out on the sea as well! The progressive level rivers will probably be the best choices for your skill level. 

You will probably benefit from some training in the wildwater boat on flatwater to improve your forward paddling technique in the WW boat. Lessons learned here will transfer back into the sea kayak pretty well also.