nabster, have a good trip, it should be easier to just rent equipments in Phuket since there are plenty of shops there. The only advantage you would have for renting it from shopsin Phuket rather than the boat is that you get to see the equipments first, if you don't like it then just walk over to the next shop however it is a bit less convenient than getting it on the boat. Renting from the boat, you won't see it until you get on the boat and if they don't fit well or not as well maintain then you are stuck. Saying that, Mermaids have pretty good reputation, I probably would just email them first and ask what kind of rentals they have, how old they are etc etc and if it sounds reasonable then I probably won't bother with renting it from other diveshops.
Fishchaser, I get seasick all the time (although as I get older, it becomes less of a problem), I have been on liveaboard on a good size boat 30+m as well as smaller one for 4-7 days trip and never really got bored. You tend to dive more 3-4 dives per day, they tend to serve food and snacks often and I tend to nap a lot between dive if I dont do anything else, I also find that even if I travel by myself, other divers are generally pretty friendly and since you all share similar interest, it should be easy to meet new friends anyhow.
Most boats will pair you up and won't charge you extra unless you request to be in your own room. If the boat is not full, you have a good chance of having the room for yourself anyhow without having to pay extra.
Fishchaser, I get seasick all the time (although as I get older, it becomes less of a problem), I have been on liveaboard on a good size boat 30+m as well as smaller one for 4-7 days trip and never really got bored. You tend to dive more 3-4 dives per day, they tend to serve food and snacks often and I tend to nap a lot between dive if I dont do anything else, I also find that even if I travel by myself, other divers are generally pretty friendly and since you all share similar interest, it should be easy to meet new friends anyhow.
Most boats will pair you up and won't charge you extra unless you request to be in your own room. If the boat is not full, you have a good chance of having the room for yourself anyhow without having to pay extra.