I think this is a "rites of passage" and present culture issue. 18-24 year olds particularly, have learned how to socialize at parties, with beer or booze, etc, and they are wanting to meet the opposite sex and "connect"..I think this period where socialization is dominant, keeps this age group away from diving, because there is no perception by this age group that they could get any good connecting in the environment of diving. Alot of this, is just not knowing what they don't know, and having other alternatives that are very easy...like bars and parties. After you do the normal social scene for this group, and work, there is not much time for scuba....not to mention the problem of a late night Friday or Saturday, and any desire to dive early, or at all the next day.
The Dive Industry "could" show how going on a dive boat can be an outrageously cool thing for a guy and girl to do together....a great way to meet another.....and without having to get blasted.....That it is really a better way to meet and to KNOW people you like.
If I am right about this....think about it as a mission...the kids want to "hook up"....and to have a shot, they need a "target rich" environment.....there are not alot of single girls with this in mind, already found on dive boats.....so a 19 year old guy that goes to a party, and sees that it is pretty much all guys, will be on there way out the door fairly soon.
If they want to bring a girl to a dive trip, the guy is going to have to get her certified first....this makes an impossible first date for the boat dive. And the idea that they get certified together--then dive---maybe if they are already long time friends, but this eliminates the majority of the socializing in this age group.
Snorkeling could work for this age group...but no one in the dive industry pushes this....the dive industry is far too short sighted. A whole group of kids could book onto a boat and go snorkeling, and then this is a group that may well decide scuba could be in their near future...with their snorkeling buddies. For this to happen, DEMA would need to popularize Snorkeling on TV or YOUTUBE, and get kids to see how exciting these snorkel trips could be--and how much better they might be than bars or parties--for what they really want. An individual dive operation can't really afford the Media Weight that would be required to popularize/glamorize this new snorkeling option for kids...This would take a large association.
As to the fit.....of course, Snorkeling is far less expensive, for a group paying off student loans and still in low paying jobs...and snorkelers like this can easily become freedivers.....and freedivers will make much better scuba divers than statistically possible with the present training agency models. And when these groups of kids would form, and have fun, you would get an explosive growth of the new fun thing to do with the opposite sex, and the kids VERY WELL COULD BECOME the BIG groups on Dive Boats !!