Anyway we get topside & I'm ready to give them a piece of my mind, but am requested by the DM not to as they would take their business elsewhere. Go figure.
And therein lies a problem. Economics is a motivator, but it works both ways.
A few years ago in the summer in Belize, I saw a father and his two sons start gearing up for the dive, and I was puzzled. Because the water was so warm, they wore only swim trunks and T-shirts. They also wore 5 mm gloves. Once we were diving, I saw why. They barely used their fins for propulsion--they instead gripped the goral and pulled themselves around. I tried to signal my displeasure, but they ignored me. After the dive, I went to the DM and asked him to say something to them. He said he would, but he obviously did not because they did the same thing on the next dive. The company must have been afraid of offending a paying customer.
Also a few years ago, I was in Grand Cayman when a diver put on gloves while gearing up. The divemaster (I will name the operator--Ocean Frontiers) looked at him sternly and said that he could be fined up to $500,000 for wearing gloves while diving in Grand Cayman. He laughed. She didn't. She calmly said, "Take them off!" without a trace of a smile. He took them off.
Obviously, Ocean Frontiers was more concerned with protecting the environment than keeping customers. It doesn't seem to hurt--the last I saw, they were still a successful and respected operator with a former customer who recommends them on ScubaBoard.
I had both incidents in mind last year when I was the designated group leader of a group diving in Ambergris Caye in Belize. We had a specific dive master assigned to us for the week. On one of the first dives, he saw a turtle and herded it over toward us. On that same dive, we saw another DM from that operator with a nearby group provoke a puffer fish into inflation.
As soon as we broke the surface, our whole group started talking about both incidents, and we were not happy. I went to that DM and made it very clear that we did not want to see any harrassment of the sea life on our dives, and I made it very clear that there would be consequences if we did. The DM was probably anticipating a whole week of tips from a large group going down the drain, and I am pretty sure he knew he would have heard about it if our LDS told the owner we would never bring another group there. It worked.
So it works both ways. If the operator is afraid to criticize people abusing the reef for fear of losing a customer, you can make it clear that he can lose customers if he does not control thosedivers as well.