It’s also two different styles of diving.....in CZM on the day boat you will get two dives, it will drop you off at one end of the reef and you will leisurely drift in 2-3 knot current along the reef and they will pick you up an hour later at you egress point. This can be a bit difficult for photography unless you slip down behind structures/coral heads to get out of the current.
On the Aggressor you’ll dive from the anchored boat (4 day dives + 1 night) and you must return to the same spot you entered the water. They will move the boat usually after dive #2 in the morning and do dives 3, 4 & 5 from the second anchor of the day. After the night dive they will move the boat away from the reefs out to deeper waters to anchor for the night (where the sea can get a bit rough sometimes).