Since I started divingin 1985 (in cold water) I have observed a few things:
1. Cold water divers tend to dive because they want to dive.
2. The cold water diving motivation may be to get certified locally before going south to dive with pretty fishes in warm water loctions and if that is the case, then they quickly convert to warm water divers who dive on one or two trips per year.
3. Some cold water divers start out with good intentions but get ruined/spoiled by warm water/pretty fishies diving and their cold water diving drops off substantially and in turn so does there total dives/hours in water per year, greatly slowing the learning and development curve.
3. If divers remain cold water divers, it is because they like to dive, and a subset of these divers will be divers who like to dive just to dive and will dive just about anywhere deep enough to fully submerge.
4. Cold water diving is a bit of a pain. Thick wet suit, gloves, hood, more weight, takes about three times as long to gear up, etc. If you doi it frequently, it is because you want to do it
5. Almost no cold water dives are destination dives where a crew or DM will set up your gear and hold your hand, so on average cold water diving requires a bit more independence and self reliance than warm water diving.
6. Cold water diving almost always means less visbility and as such usually offers more demanding conditions as holding depth, maintaining a slow rate of ascent in mid water with no surface or bottom in sight is much more difficult than it is in the ocean where one or both are often in sight, maintaining buddy contact and navigating during the dive are all more challenging. Plus a 100' dive in cold water is almost always dark, cold and limited visibillity whereas a 100' tropical dive is warm wit both surface and bottom in sight and is more of a thing of being able to look up and note that the boat hull looks smaller than it does at 20'.
7. Cold water diving offers less in terms of pretty fishes and margaritas on the beach, and often takes a hit as there is "nothing to look at". But on the other hand, a warm water reef is analogous to an oasis in a desert while cold water marine environments tend to have more flora and fauna and almost any body of freshwater is jam packed with life above 30-40 feet. So beauty tends to be in the eye of the beholder and my biased opinon is that cold water divers tend to appreciate the more subtle beauties of cold water more than warm water divers. Whether that trait develops because they dive cold water whether that is a motivator for diving cold water in the first place is open to debate.
8. When cold water divers get bored, they work on new skills, new certs, etc and in effect become better divers.
9. When warm water divers get bored, they move to new destinations, move on to different sports or buy a Harley.
10. The end result I think is that dedicated cold water divers are on average more skilled because they dive more, dive in more demanding conditions and over time dive in a much wider array of conditions and become much more experienced and well rounded as divers.
11. The differences within a group are usually as large as the differences between groups and the same thing applies to cold and warm water divers - there is a lot of variance.
