UCFKnightDiver
Contributor
Skills to be learned as a cave diver:
Buoyancy & Stability
Clear winner: Mexico.
There's little-to-no flow, so you don't need to kick. Constantly kicking can hide buoyancy and stability issues, whereas holding completely still in placcid water exposes all.
Flow
Clear winner: Florida.
There's only a small handful of places in Mexico where there is appreciable flow. And even there it makes Ginnie on the calmest day feel like a firehose. To learn to read the cave and position yourself to deal with flow Florida is the place to do it.
Linework
Mexico by a nose
In Florida you learn to deal with a reel in your hand while dealing with flow. In Mexico you learn to do it holding completely still. There are some nuanced differences to the line-running philosophy in either place, but essentially you're going to learn how to not make a mess of string in either.
Thing is, if you can do it holding still you can learn flow. If you only know how to do it in flow you'll be bouncing off the floor like a rubber ball when the flow is taken away.
Navigation
Clear winner: Mexico
In Florida there's usually one way in and one way out. All the arrows point there. In Mexico there are thousands of feet of line per acre and the arrows could be pointing at an ant-filled hole in the middle of nowhere.
Time in the water
Clear winner: Mexico
As noted above, the depths in Mexico are significantly more shallow, so there is potentially a lot more time in the water. I find this is incredibly useful as divers learn skills like backreferencing, remembering landmarks over the course of a dive, and learning to calculate gas planning and management. Whereas in Florida there is a good deal of, "We're going to swim in for 15 minutes and then come back out."
Gas planning
Clear winner: Florida
No one uses the same tanks. So dissimilar gas matching is a thing that you'll do on every dive. In Mexico, with little exception, everyone dives AL80s. That makes figuring turn pressures pretty easy.
Deco planning
Clear winner: Florida
After even some of the longest dives in Mexico it's barely worth the bother of gas-switching to O2 to clear your 5 minutes of deco.
Teamwork
Toss-up
Team dynamics in single file vs. being able to get together in a circle (dictated by the flow) are a little different and both useful skills.
Yeah, exclusively Mexican-trained divers tend to get their asses handed to them by flow, tend to be timid when they're first introduced to pull-and-glide propulsion (or pull-and-pull-and-pull-and-pull-etc), and the first time you show them a set of backmounted 104s they pass out like a victorian matron. However, generally {puts on helmet and ducks behind couch} in my experience Mexican-trained divers tend to have a lot more control and be more adaptable.
In the end:
There are great instructors and awesome caves in both venues. One way or the other first or second, exposed to them both you're going to be in good shape.
Plenty of low/no flow caves in FL too, not everything's like Ginnie