When you have the time, click on my webpage
Jim's Web Page for many years of trip reports to Scuba Club Cozumel.
Here's the short version: You can either enter the water by a giant stride off the pier or walk down a set of stairs into a protected "well" and then swim through a cut to get off shore. The current normally runs South to North, so you will want to start your dive into the current by turning left out of the cut. Don't rush, move slowly, look for small stuff. If you parallel the shore line, you will swim under SCC's pier, over lots of concrete rubble, past the second pier - off to your right is the pyramid. When you have burned through 2/3rd of your air, turn and drift (no need to swim) back to the exit point. An alternative is to swim directly out (West) to the remains of the old pier, an artificial reef with lots to see, then turn South into the current as in the previous example. Depth = 20 feet, you can't get lost. The third alternative is to stay in front of the hotel, visit the artificial reef, poke around the pier, look under rock piles, etc. until you run out of air - about two hours of diving.
The lighthouse drift - get a cab to the lighthouse, drift back to the hotel. It's probably better if you don't do this dive until you have done a normal shore dive - that way you will know when you are back at the hotel. (There are only two piers between the lighthouse and Scuba Club).