@Hoag yes these are very helpful tips! Thanks so much! Mid-80s sounds like the perfect temp and I'm looking forward to seeing all the sharks!
It was my first liveaboard, also, and I think the Turks & Caicos Explorer was a good fit for me. My general liveaboard advice is to look at previous Scubabaord threads and blog posts with packing lists and other tips. The highlights would be:
1) try to stay warm - the cabins and other indoor areas of the boat will be very cold and I'm glad I brought a heavy hoodie. High volume diving is taxing mainly because of the heat your body is trying to produce to compensate for heat loss during dives. I'm not a "laying out" person but I also found it helpful to get 20 minutes of sun on the deck once a day. Also, the water temperature was very warm (usually low 80s) so my warm 3/2 full wetsuit was just too much and I was glad that I had other thinner thermal layers as an option. However, I still think it was wise to bring the full wetsuit, as it's likely better to err on the side of too warm than too cold. My 3mm tech shorts, and combination of 1mm hooded vest and long sleeve shirt ended up being what I used most often.
2) try to stay dry - I always tried to change right away after dives into dry clothing to help me stay warm and also to help my skin. Being wet all day for days on end can cause other skin issues and irritations. I suggest bringing a lot of swimsuits or undergarments so you can always change into dry clothes right after a dive, while other swimsuits are drying. I brought only three t-shirts (I could have done with two) but brought a lot of shorts and underwear. The other woman on the trip had some very light dresses that seemed to be pretty versatile for her.
3) think about bringing a GoPro or other underwater camera - I wasn't going to bring anything to record but bought a GoPro the last minute and I'm glad I did, but I'm glad I didn't bring my laptop
4) think of any physical or mechanical problems that could prevent you from diving or enjoying your dive, and research the best way to prevent them. This is vague but an example for me is that I usually get bad blisters/wounds on my middle toes from fins. I did some research and bought lycra socks and some silicone toe sleeves and I didn't have a single issue all week. I couldn't believe it. Similar to issues with swimmer's ear, dehydration, computer batteries, etc.
We only had five passengers and five crew. That is not typical. Normally there are more passengers but covid is hurting the liveaboard business. I wouldn't be surprised if your trip also had fewer divers than usual. Personally, I liked having fewer people because there was more space for gear and I never felt crowded. I was a single diver, so it would have been nice to have a couple more people to socialize with but I'm very happy with how everything turned out.
Any other questions?