Nice port, no beach. Just walked around "Old" San Juan. Beautiful area right out of a Bond flick. Visit forts, shops and senor frogs. You are only there for 5 hours but if you are not expecting much, it is nice to just walk around. I did not try an excursion so you might want to try one.
Excellent location to stop at. We walked to the beach from the ship 15 mins. Go towards shops and you will run into the beach. Natives will bother you but were nice about refusing service. Nice beach and nice water. Did not try food or beverages although I saw plenty of places to eat and drink.
I suggest an excursion of some sort for this port. We tried to get a cab to a different part of the island that wasn't where everyone else was going like Megans beach but no one would take us to the secluded places. It was nice there but we didn't do anything fantastic.
We ported at Samana, Dom Rep. Read bad reviews about Samana itself and took the recommended excursion, a boat ride to Cayo Levantado, a private island off the coast with a beautiful beach and clear water. We rented snorkel equip and canoes for 2 people for only $35. PLayed volleyball and had good cheap food and drinks. Best part of our trip. Walk past the small shops because the natives are pesty. Great island trip. Book with cruise line on board, it's only $15 each. Cheaper than website.