On our last cruise I became quite friendy (in her favorite break lounge) with a woman from Shore Excursions. She told me that the three Princess offered going to Hato Caves were almost always fully booked early. Guess some must like doing it.

Did notice that all three (Hato) were marked M (moderate). The Harrison's Caves excursion in Barbados is marked E (esay) ... so thinking there has to be a difference in the mobility level needed ....