Most people bring a bag with them for towels and belongings. There's not a designated area for them but they are usually safe anywhere on the boat. Over 10 Boobs Cruises and unless you count the shorts I forgot on the beach I haven't lost anything yet. Obviously don't bring anything you would cry about losing. I actually wear a stunt ring instead of my diamonds because I have seen people lose them on the boat/beach.
We usually just bring a beach bag with a draw string and put stuff inside. It might be a good idea to put things in a ziplock bag for a little extra protection also. (Stephie takes care of packing it). About all we bring is sun screen, and maybe a small camera, some tip money for the crew and the lunch staff on the island, and that's about it. Last time we had several cans of colored cake frosting and as you can imagine that was a sticky, but very fun mess! Then just tuck it under the mast in the center of the boat or someplace that it won't be a tripping hazard and it's GAME ON! So far the only thing we've ever lost has been our dignity, but to be honest it was kind of misplaced long before we got on the boat. Happy sailing!
Photographs, like at Temptation, while not said, are frowned upon, unless they only are of you and your partner or scenery shots... imo... While Temptation is no-one knows and no-one cares, the Boobs Cruise is more so, with people being more extreme, that probably/definitely don't want photos appearing on social media of them! Most people have a bag to put the essentials in - suncream, towel, cover-all for island, tips etc. The bags are simply left out of the way of foot traffic on the boat but there are no secure areas. There are a limited number of people on the boat, known by Steve, so potential thefts are limited to whoever may be there... However, I wouldn't bring an expensive camera because 1, you would have no use of it, 2 unless you carry it there is no safe area, 3 if you carried it with you, other people may object...