Favorites:
1) Fresh-cooked meals or snacks between every dive to refuel - my favorites are the Euro-style boats where they have a "continental" breakfast (coffee, breads/pastries, cheese, fruit) before the first dive and then take your order for a cooked-to-order "real" breakfast following the first dive.
2) Deck showers conveniently located where you take off and hang your wetsuit - best when they maintain a bottle of shampoo there or even better, a shampoo dispenser.
3) Utmost convenience for photographers/videographers - on many boats you never have to carry your bulky heavy system, just point out to a deckhand which camera is yours and they load it on the dinghy and hand it to you when you're in the water; hand it back after the dive and they get it back on the liveaboard, rinsed, and sitting on the camera table waiting for you to dry it and start fiddling.
4) Far more social interaction than day-boat diving since you live in close quarters with these people for a week or more, which means more time to explore each other's diving histories and realize that the "seven degrees of separation" is more like one or two degrees at most when you get to talking and find out you know someone they know in the rather small universe of avid divers (and being on a liveaboard usually qualifies one to be an avid diver).
5) Unlimited nitrox. I hate day boat diving for making me undergo the cost-benefit analysis for each overpriced tank that I want to dive. It's a far simpler and much healthier calculation to fork over a lump sum and then dive nitrox on every dive. I just wish that they'd take a cue from dive ops in Bonaire and offer the nitrox for free.
Dislikes:
1) Stuck in a small, sometimes stuffy, sometimes stinky, sometimes wet cabin, many times suffering a small uncomfortable bed, and sometimes sharing your shower with the rest of the "head" - worst was the O____ A_____ (don't want to name names of course, but it's a liveaboard that plies the waters of a certain island way off Costa Rica): We were instructed to throw our used TP in the wastebasket ("Mexican style") instead of in the head - they assured us they'd change the wastebaskets daily, but they didn't. Furthermore, the cramped cabin (smaller than most liveaboards I've done) had a severe mold issue growing on the very weak A/C vents. We were stuck in that humid hot hellhole for 10 nights, and paid darn good money for the privilege!
2) Why do non-drinkers take alcohol-inclusive boats when alternatives exist?
3) Sometimes I'm not the a-hole of the trip, it's someone even more an a-hole than me
4) Broken things: When you're in the middle of nowhere, stuff happens and sometimes it can't be fixed, or even when it can be fixed, it leads to delays. This applies to mechanical problems (broken hot tubs, broken outboard motors on the skiffs, broken marine head system, broken main engine, broken alternator (no electricity), broken plumbing (no water!), broken hot water heaters, etc.). I've suffered all of those at one point or another, but fortunately never suffered a broken compressor so at least the dives could go on! This also applies to human problems: having any sort of incident on a remotely-located liveaboard (I don't mean Palau, where you're only an hour away from town) can suck big time, though I have found that it's a rare liveaboard that doesn't have at least one MD passenger aboard for good luck.
5) I hate when they provide shampoo by the deck shower, but rarely refill it.
6) 28-hour days are really required in order to get in all the day's dives, meals, socializing, and still have enough time to fiddle with the camera in between. I've actually been exhausted enough to sit out a dive or two during the week, but nearly always regretted my decision and regretted it the most during my Bali-Komodo liveaboard when I sat out the one night dive when we finally had a chance to spot stargazers. I'm still kicking myself over that one and will keep kicking until I hopefully someday have another chance to spot them.
