The first time I dived Barracuda/San Juan, my feeling was "What's all the fuss about?" There was no current at all. We could swim in whatever direction we wanted. It was one of the easiest dives I ever did on that island. I did, however notice that the barrel sponges were twisted and deformed from the current.
The second time I dived it I saw precisely what the issues were. The current was doing its best to sweep us off the reef, and we had to be both skilled and strong to fight it. It would have been a disaster for a beginning diver.
When I dived Barracuda there was a down current that gave the group a bit of trouble. I had to inflate my BCD, a little bit, to get up on top of the reef. After the dive, the guide ripped into me about using the wrong fins; I was using spilt fins. Jorge, the guide, told me I should have been in blade fins. With hindsight I agree with him. The experience was a learning one - use the right equipment for the environment and pay attention to currents.
I haven’t been to Cozumel in years. It is place I would like to go to again hoping to dive Devil’s Throat and the north end of the island.
With everything that has been said on this post and working at a resort as well as diving and teaching in high elevation lakes (in short gaining a lot more experience) I like it when a dive-op conducts check out dives. When I did a study abroad in Egypt the guides did check-out dives. I was able to do things other divers were not, which was rather nice. When I lived in Cayman I saw all sorts of people at various levels. Luckily I didn’t come across a lot of incompetent divers to guide. What I did notice was a lot of people don’t know their gear. Part of my job was changing tanks during the surface interval. I probably learned more about gear than the customers learned about their own gear.