Just returned from my 10th visit to Santa Lucia. It is one of our favorite vacation spots because it is so laid back. Nothing fancy about any of the hotels, and I personally love Caracol the best.
Small 3 star, no fancy food, but great burgers and fish at the beach grill, and the buffett has variety, although after 2 weeks can become repetitive. I usually go for pasta....
As for diving, I've never done it, however, I do know that they have shark dives in Nuevitas bay. Good snorkelling at the reef not too far from shore.
Nice beach, good cold beer, and best staff I've ever encountered.
Happy Holidays all!
Beachlovertoo.