I would give it a zero, if possible. Five minutes into the swim, a fellow cruise passenger was not feeling well and they sounded a horn signaling that we should all return to the boat. From that moment onward, the sheer incompetence a lack of preparedness of the local folks to deal with a situation like this were more than obvious. It took forever to reassemble all passengers (who could have been left with other ships in that area), there was no emergency plan, and when we got back to port there was no ambulance waiting (this part really shocked me). Perhaps as a result of all these factors (or with their contribution), the gentleman did not survive.
Cruise ships are ruining this place. There were five large ships already docked when we arrived and traffic (cars and people) on the island is absolutely chaotic. Not a pleasant experience at all.
There is always something interesting or beautiful to be seen in Puerto Rico, a place I visit on business several times a year. We really enjoyed our day in Old San Juan.