Each of the three times we've been to PR, we've flown into San Juan.
First time, we stayed three days in Old San Juan, and then drove to Rincon to dive with Taino at Desecheo; and then drove down to La Parguera for one day to dive with West Divers on the wall.
Second time we stayed four days in OSJ, then drove to Playa Santa and dove with Island Divers on the wall off Guanica.
Third trip, we stayed one night at the San Juan airport hotel, and then flew to Culebra for three days to dive with Culebra Divers, and then back to stay in OSJ for three days.
While each trip was intended to be a dive trip, what we found after our first one, was that a trip to Puerto Rico without a couple of days in Old San Juan is a wasted trip. There is so much history and depth of attraction in OSJ that is should not be ignored.