Ouch. Sorry to hear about your back spasm. I've been there..if I might be so bold, I found the book "Ultimate Back Fitness and Performance" by Stuart McGill to be really helpful for long term management.
The diving was fantastic. Sea Fan Grotto, Crane Point and Eagle Reef were the spots we dove, IIRC. The Isthmus (?) had too much current. Vis was fantastic for the first two dives, and acceptable for the third. With water temps in the 70's, it's damn near tropical.
We found a couple Moray's, a bunch of lobster (who will go into hiding in a few weeks no doubt) and saw some lovely butterfly fish!
This was my first trip on the Magician, and I was very pleased. The captain and crew were great, and the value was fantastic. I'm going to try and make a couple more of these Wednesday trips before the weather gets cooler.