Shasta_man:30-60 minutes travel to the sites? Not our experience at all.
One day we went to Ulong Island and dove all day at spots nearby and the last day we went to Jellyfish lake and then onto the Iro. Otherwise, we anchored in the middle of the channel and dove the spots around the compass at the islands you can see from the ship.
We did most of those places as well. However, the least amount of time we ever spent in a chase boat was 30 minutes.
I guess it depends on how far you decide you want to go & whether or not they have their chase boats/RIBs picking you up (which held true in the Red Sea).Diving off the stern can be good, but also means you come back to the boat, not the boat comes to you.