NOT swimming The Channel

I have had a fascination with swimming the Channel for about a year now. Its 21 miles, as the crow flies, and the average time it takes is between 10 - 20 hours. It took David Walliams 10 hours 34 minutes.. and 1 more Wiki fact.. less than 1000 people have ever completed it! There is no doubt that I would do it but for my terrifying fear of the sea, slight obstacle....When I am in the sea I have to be able to touch the ground, and any passing seaweed or dark patches of water send me into silent screaming. I've thought about hypnosis, but it will be a waste of 'going under', I get the fear that a shark is on my tail when I'm swimming lengths in a kidney shaped pool. I recently read about a guy called Dan Martin who is about to embark on a Global Triathlon, which includes swimming the Atlantic. Setting off from Nova Scotia with nothing more than his speedos, ginger beard and goggles he is going to swim 8 hours a day for about 4 months until he reaches France. He is going to wear a shark repellent anklet and won't be swimming at dawn or dusk (shark feeding time)...I don't know if Portuguese Man-of-War can kill you but now I've just seen a picture of one I know they will be joining me in the pool next time too. I'm such a WEED!