I'll be travelling in May with a companion who is a little bit fussy about wanting the warmest possible ocean swimming situation. We're looking at either Corsica or Sardinia (but I'm open to other European locations with warm ocean swimming in May!). Which of those two places might have the warmest water temperatures in mid-May? Any particular beaches in either of those places that you would recommend as being more likely to be warmer?
We're in our 40s, mellow, love beautiful scenery, poking around villages, local flavor, museums & the like. He really loves beautiful beaches, so for our first trip to Europe together, I thought I'd try to find him some lovely and swimmable ones. We'll be renting a car. All suggestions so appreciated! Many thanks!