I mean, I enjoy places where I can swim - like the cruise in February hit the spot since I could swim in the ship's pools, at beaches and waterfalls in St. Maarten and the Dominican Republic, and I participated in - and won - a synchronized swimming competition on the cruise...possibly due to my swimming partners being two really cute little girls.
In any case, swimming holidays may be more of a British thing - or at least a non-US thing. But, as a former competitive swimmer, I can appreciate the idea. Though, the "swimming holiday" of renting a beach house and going there for a week is nice too. ;)
"The Guardian" put out this list of Top Swimming Holidays. Locations include Croatia, Egypt, Greece, and even a couple in the U.S. like Lake Powell in Arizona and the Little Red Lighthouse Swim in NYC.
There are actually a bunch of swimming events in the city, which I really need to start checking out. Ya know, if I ever actually do want to swim the English Channel.