Hi Marshmelo,
We just did this excursion in June and we had a great time. I would definitely wear swimsuits. They have a bathroom but nowhere to chage and it was quite crowed.
Bring your own snorkel equipment if you have. We had some trouble with the masks staying on really tight.
They have water on board (little cups), but if you want to bring your own, buy the bottles on board because the bottles that are sold at port can be pricey.
Sit up front near the nets so you'll have extra leg room.
We didn't have any problems with people touching our bags, but you might want to invest in the plastic box that is waterproof and hangs around your neck. This is great to take everywhere for your cash, drivers license and KTTW cards. They sell these on the ship. I also brought a safety pin to secure it to my bathingsuit top. Last year at CC, when I removed my life vest I pulled it off and didn't notice I had dropped it until later. I did find it half buried in the sand!
If you have a plastic beach bag this is ideal. It rained on us as we went out and our towels, coverups, sandals etc. got wet.
Be one of the first off, because there was a long line to get off into the water. We had about 10-15 minutes less of snorkeling because we waited "to get in line". This is also another reason to sit near the nets. This is where most people enter the water.
It really was very beautiful. And the ride is very nice.
Have fun!!!
