Boat diving course?
Five minutes talking with an experienced boat diver is all it takes to learn some of the vagaries of boat diving without having to pay PADI for another card.
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Very true.
I've been diving over 30yrs, much of it married to a non-diver. Until my 16yr. old got certified (at 14), I either dived solo or with an insta-buddy, depending on the boat and whether or not the cap'n/DM's knew me.
There are plenty of insta-buddy horror stories (and I can related a few), but my experiences have, overall, been very positive.
I enjoyed diving with newbies, especially divers on their first few ocean dives. A shared experience is always better, IMO.
These days, I have a slave-buddy. On a recent trip to Florida, I was asked to add a 3rd member to our team, an newby who needed to buddy up. I said, "No", not because I didn't want to share, but because I felt my attention need to be on my son 100% (even though he has nearly 100 dives and is very good) and because I wanted our dives to be long (newbie was on air, we were on EAN). Even on air, we were often first in, last out and my teen was having a great time, so we decided to be selfish.
Insta-buddies are great, but the option to dive/not dive with them (or them with you) should always exist.