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Rule number 1: When drift diving, you do not need to kick! I have no doubt this is why you got ahead of the DM. Find your neutral spot and let the current carry you. If you get ahead of the group, turn around and kick gently into the current to wait for them. Stay close to the bottom and close to the reef (without bouncing off the bottom or running into the reef) The current is typically stronger the further above or away from the reef you are.
Rule number 2: Do not get down current from the DM. You weren't keeping up with him...you were ahead of him, huge difference. You are not expected to anticipate where he is going, that is why he is leading the dive and why you are supposed to follow...not the other way around. This is just one reason (among many) why divers are required to dive with a DM in the water with the group at all times in Cozumel.
Rule number 3: Unless your life is in danger or potential danger, DO NOT TOUCH THE CORAL. Getting ahead of the divemaster and pulling yourself along the CORAL (not rock) to catch up to the group to go through a swim through is unacceptable and completely unnecessary. The correct thing to have done having found yourself in that situation would have been to wait. They're still moving in your direction.
If you cannot pause and hover (part of buoyancy control), then I would highly recommend a buoyancy course. This will help you improve in many aspects of your diving. With less than 50 dives as your profile indicates, you are still considered very new divers and still have alot to learn. That's not a bad thing, just a fact. We all started somewhere, and as long as you recognize that...you will continue to grow and improve as a diver.
Perhaps after observing you, he was trying to keep you away from heavy currents since you seemed to have difficulty with them (not able to stay with him or the group). That is actually a sign of a good divemaster and I commend him for that.
You say that no one talks about this side of Cozumel much? That's news to me. Cozumel is famous for drift diving and that's all we do here because we do have currents. Some days they are stronger than others, some sites are stronger than others. They are unpredictable for the most part. For those who are not comfortable with drift dives, then I don't recommend Cozumel...because every dive here is a drift dive...whether you're flying thorugh the water or gently gliding along. Another option is to hire a private divemaster/instructor until you are comfortable and controlled with drift diving.