First, welcome to the addiction.
Second, It would add a couple of hours to your day, but you could take the ferry over to Cozumel for $10 ( there was an $8 option 2 weeks ago, but I heard they were shut down) and there are lots of shops that offer world class Valet dive service with every kind of reef you can imagine. From Deep swim throughs to shallow fast drift dives loaded with life (my favorite) it's all there. Most ops leave early so the first ferry out would be needed. The ferry takes around 40 minutes each way.
We dive with Aldora who use steel 120 tanks standard so you end up with 90 minute dives. Their pier is right next to the ferry pier. The standard tank on Coz is an aluminum 80 for most other operators, with an option of an AL100. Depending on the group and you personal consumption, dives over an hour unless you stay shallow are rare. We love the big tanks!
Blue Magic is a few blocks from the ferry pier, but an easy walk even if you were dragging equipment. Again fantastic service that I can personally recommend. A small shop that is literally like diving with family. I think they left their shop around 8 so it would be doable from the ferry.
Dive With Martin is one of the oldest and cheapest operators on the island. DwM leaves from their shop next to the international cruise ship pier, proabably a 5-10 minute cab ride from the ferry pier. When we dove with them there were 4 of us so it was just as cheap to charter our own boat and have it waiting on us when we got off the ship. That was our first dive trip after certification and we have been hooked ever since.
blue XTSea I believe has a dive trip for cruise ship divers that leaves a little later as well. There are tons of other operators on Cozumel and we have never had any bad service. Tres Pelicanos, Papa Hogs, and Living Underwater all get good reviews as well. As long as you are on a small, fast boat with no more than 6 divers, I think you will be pleased with the service. The only bad reports I have ever heard were from divers on "Cattle Boats".
All the ops I mentioned will have great email response times and may have a special dive schedule leaving later. Just email, explain your needs, and I bet all of them will work to accommodate almost any reasonable request.
If the Cozumel option interests you, there is a specific forum with literally a weeks worth of reading on who to dive with and what to do. We go at least twice a year and consider it our second home. If you have any questions, feel free to pm me.
Third, regardless of where you dive or which operator you choose....prepare to be amazed. It's almost impossible to get excited about a lake dive after Cozumel.
Good luck, safe travels,
Jay
