Interesting discussion. As two old farts in their 60s, our live-a-board experiences the last 10 years has been outstanding. We could not do these trips in our 20s (not enough money), in our 30s or 40s (kids, college expenses, etc.) and have just been doing them the last 10 years. We travel with two LDS groups (I am an very part-time instructor for both shops). One group is mostly late 20-30s and the other is mostly 50s-60s. We enjoy being with the young group and think they are ok with us. We have a few 20-something folks (singles) with our older group and they have joined the trips every year for the past 5 years. We talk diving. That is the common thread and it's a blast talking to folks with 1000+ dives and folks with 50-100 as well as folks of all ages. We also talk about whatever seems fun and have built relationships with all ages. As a 20-something, you are our kids age and we need all the insight we can get, so you might have to fend us off from seeking constant advice from you. Most of my dive pals around my age have more to chat with you about then you might realize. One of our 20-somethings in the older group invited some of us to her PhD dissertation. I didn't understand a word but it was cool to be there with her family to support her.
You will be able to find younger persons' live-a-boards...Blackbeards, some Aggressors, etc. When you start looking at the Coral Triangle, etc. it's bigger bucks and those of us who have freed ourselves of house payments, kids' college costs, etc. have an easier time doing this. Also, time off. I could not take 2 weeks for a single trip until into my 40s. Now, who cares? Finally, heavy partying on a live-a-board is rare
so us old folks won't cramp your style. Hook-ups however, you can kind of forget it on our trips.
Don't despair. Look for travel groups or LDS shop trips and ask about age make-up. Keep diving and you'll find your sweet spot for group make-up.
Rob
