Do you know where you'll be staying? I have some recommendations, but
depending on your location some will be more practical than others.

Generally speaking, you can expect to have guided dives. Typically the
dives will be 35-40 minutes as a group. The ops provide al80's and
weight belts. You can choose boats ranging from 6 packs to big Newtons
carrying 25 or more divers. I know a lot of folks dislike the
"cattleboat" idea but given the generally windy conditions (meaning
big rolling waves) this time of year there, there's something to be
said for a wide stable platform under you. The reef area to the north
end of the beach is nice, about 55-65' deep and slightly deeper if you
dive the minesweepers.

The training dive and resort course dive area is closer to the hotel
zone in the channel between Isla Mujeres and the top end of the
lagoon. Chitales is only about 25' deep and has nice reef structure
with lots of Southern Sting Rays. Over closer to the island the dives
are slightly deeper at 35-45' but lots of fish and structure.

I haven't had very good luck with dives at Punta Nizuc (south end)
because of surge and lots of stirred-up sediment so I avoid trips to
that end of the lagoon.

For something different you can take a day trip with many of the ops
to Cozumel for about $120 all incl. This gets you a bus ride, ferry
ride and two tank dive with shore lunch and some shopping time
downtown.

They also offer cavern day trips to the Akumal area. Not something for
the claustrophobically inclined but fascinating otherwise.

You can also rent a car and plan your own day trips. There are ops all
along the shore south of Cancun, many within an hour of the hotel
zone. Often you can simply get on boats with no advance planning and
get in morning or afternoon dives. There are cave guides available who
will take you for a day of guided cavern dives. I know a few of them.
In fact one is a young feller from my home town. He's a great guide
and a very conscientious diver. He won't let you get beyond your
ability. I have a few other names of operators I've diver with in
Cancun and some who run shops south of Cancun in Puerto Morales,
Puerto Aventuras and Akumal.

Email me if you want more specific info.

Hope this helps
JF CID
"It's a damn poor mind that can only think
of one way to spell a word."
- Andrew Jackson (1767-1845)

I was there last March break. Dove with AquaWorld, they're located on the
main strip.

Was very pleased with their guides, dms, crew and itineraries. They also
have their own boats, good sized ones too.

They have a variety of packages if you want to make multiple dives. I did 3
dives with them in Cancun at various locations. One of them was my first
night dive - what an experince, blew my mind!!!

The day dives had about 18 divers per boat, fairly large boat so it didn't
feel like a cattle boat. We broke up into groups of 6 per each DM which was
good. Leasurely pace through the sites, wasn't rushed at all. DM took the
time to point out some unusual features and creatures. There were pre/post
dive briefings which was helpful to set up your dive computers and logs. The
night dive had only 3 divers total plus the DM that night so we made the
most of it. Light refreshments and fruit was also served on the boat.

AquaWorld also arranged a dive trip to Cozumel - another one of their
packages. They took care of all the transportation - buses and ferries
to/from the Cancun location. Did 3 dives in Cozumel at various locations.
The wall dives were amazing. They warned us about the strong current along
the wall, down below it sounded like a freight train passing by, needless to
say, we stuck real close to wall as was advised. The service in Cozumel was
just as good by the staff.

AquaWorld also offers boat and jetski tours of the Cancun area aswell.
We/family did take on the Jetski Jungle tours - kids really enjoyed it.
There was a stop at a shallow reef for snorkling, tons of fish and rays. It
was a popular feeding site since a lot of jetski tours showed up there. Saw
the biggest barracuda of my life, about 5 feet long and just hovering over
the coral, glad it kept its distance.

No ill experience, just positive. Would dive with them again.