We didn't book excursions through the cruise line for either port.
In San Juan we got off the ship & found someone to take us on a mini tour of the area for $10 per person. It was an awesome little tour, he stopped at the points of interest we wanted to see, stopped at a souvenir shop, & then he dropped us off at the ferry to go across to Bacardi. (Bacardi didn't open til an hour after we got off the ship anyway) For about $1 round trip we went across, got a cab (I don't even remember the fee but they came back to get us when we were done too!) and they took us to Bacardi. We did the tour, drank our free drinks and did some shopping in their gift shop. A word of advice, if you have to buy something at Bacardi only buy the item that's ONLY sold in their gift shop. The other things they sell can be purchased in the store at the port/terminal building for WAY LESS. (Example, we bought bottles of the mixed drinks like Hurricanes, etc., for $7.99 at Bacardi then found them for $4.99 at the port) They also give a lot of free samples in the port stores

We had lunch at Senior Frog's, if you grab coupons as you get off of the ship you can use it to get a free shot glass from Senior Frog's. It's plastic but it's still a cute souvenir.
In St Thomas we found someone to take us to Coral World for $5 per person & he agreed to come back at a specific time to pick us up. (He is known as Green Eyes and you'll see why if you meet him!!) Coral World was great, some of our group did the helmet dive & some of us just explored and then relaxed. (The Shark Bite drink is great but VERY strong) When Green Eyes picked us up he took us on a scenic drive back, stopped at an overlook where we took awesome pics of the ship, and then took us back to our ship. A few of us went to the sky ride thing up to Paradise Point and drank Baileys Bushwackers YUM!! I loved St Thomas!!
I'm sure I've forgotten things, but send me a personal msg if you would like to know anything else

I lose track of where I post things!!