Eat Breakfast at Estelle's Dine on the Sea for Sunrise View & Estelle's Egg Sandwich & coffee & sand for your feet!
Try a night snorkel/dive at Hol Chan
Fish, snorkel then shore lunch -Mexico Rocks one of my favorite spots
Rent a Golf cart for exploring at least one day
Walk the beach and stop at the variety of watering holes
Bring eyeglasses to donate to San Pedro - Town Hall
Avoid walking barefoot while drunk or at night this prevents nasty bites from coral rocks glass bottle caps decks cement etc.