For a variety of reasons, I virtually never write reviews to post online. But Aquanauts Dive Adventures in Puerto Morelos, Mexico has made me want to write this one. The shop is small. William Alvarez and his wife Crescent own and run it. You could not ask for more personalized or friendly service and assistance. My wife and I have been diving since the early 90s all over the world, including many very remote places. We have been lucky to be in a situation where we almost always are part of a group of either four or six divers with either a 2:1 or 3:1 client/dive master ratio. Many times it has been just us. When we booked our vacation to Mexico, we thought that this luck would run out as our internet research appeared to tell us that much larger groups were the norm. That pleasantly turned out to be different with Aquanauts.
This was not a diving vacation for us (we always dive as an add-on, it is not the focus of our travels). We did two days of diving, and one night dive. The equipment (BCDs and regulators) were new and first rate. William led each of the dives. Although I cannot seem to find it now, I did at one point find a review by a very experienced commercial diver who had nothing but great things to say about him. The reef off of Puerto Morelos is well worth the trip. We heard from some other divers that other places along the coast, such as Akumel and points south, were not that good. They strongly preferred the reef off of Puerto Morelos. If you do a morning dive there, the town has many worthwhile lunch options.
In sum, Aquanauts is well worth the detour if you are not in the immediate area.