Couples Swept Away (CSA) does two dives in the morning, coming back to resort in between. That I remember, same for all the four locations.we looked into an all inclusive many years ago that offered "free unlimited diving". turned out they only took people out for a single tank in the morning and again in the afternoon.
after looking into it further, we were told even getting a dive reservation was near impossible.
so we never went. hopefully things have changed.
Good professional dive staff, equipment and boat. Bonus, Couples Resort are a no-tip resort including for dive staff: a good way to loose your job there is to accept tips.
Been going to couples for a decade or so, in between other spots