Thanks for the added info. Each dive destination has its pro.s and con.s. I like to find out what they are for each one. If Puerto Rico's value draws partly on the topside attractions, someone who 'just went to dive' might miss out. I've been, oh, I think 3 times; once 3 days at the Hyatt Dorado right after a honeymoon cruise (pretty grounds), and twice single days on cruise ship stops. We toured a fort, and my wife rode a Segway on Puerto Rico.
Richard.
We usually plan our two vacations a year around diving. Old San Juan, as we admitted to each other during this trip, would be one of the few places we would book, and not take our dive gear.
On the other hand, I would also not have any problem with simply booking a trip to dive the La Parguera wall, we think the diving there is extraordinary. We booked into Playa Santa to be closer to the diving, although the community, itself, lacks a lot when it comes to things to do post-dive (like eat out). The first time we dove down there, we went via the town of La Parguera, which does offer more (not a lot more) in terms of dining options, but is still limited.
However, since to get to either Playa Santa or La Parguera, there is a high probability that you would fly into San Juan Airport, we would be hard pressed not to plan at least a day or three in Old San Juan, or vice versa.