Read!

During noontime sunrays could be too painful so it's better to wait until around 4 in the afternoon before resuming your swimming.

What to do aside from eating, eating, and sleeping?

Read.

Here's my current book, Carrie by Stephen King. You'll never go wrong with any of his books. Let's you scape the afternoon heat while bringing you somewhere creepy eh!

And here are the front and back flaps of that book.

I recommend short stories or novellas just so you could finish it without having to literally leave your vacation and go somewhere where imagination will take you.

Always bring a book when going to a vacation. You never know, flight could be delayed. Keeps you company!