Hi Scotty
I wouldn't put myself in the same category as Tom Cunliffe! I did a talk to a couple of yacht clubs last year about my Fastnet experience, which seemed to go down well, and now I am putting together one about this year's Triangle race. I don't think you have to be successful in such events to give an interesting talk. In my experience sailing club members are pleased to hear about anybody's real experiences afloat, near of far, especially if there are some nice pictures to look at!
Have you appraoched any of the gear manufacturers? We went to an open evening at a nearby chandlery last year, and a chap from Gill gave a really informative talk about the changing technology of waterproofs. And another guy gave a brilliant demo of how to use West epoxy. Both could easily have gone on longer, and kept peoples' interest.
I think some of the safety equipment people do really good presentations as well, and getting sailmakers to talk about sail trim and riggers to talk about disastrous failures also always goes down well!
Hope that helps