It's not so much a "we all pile on to a couple of boats and camp on the island" thing as a "we all get ourselves to the island and camp there" thing. It's pretty much up to each person going to make their own arrangements, except that a camp site on the island has been reserved than can accommodate 30 people.
If you have a boat, you're encouraged to bring it. If there is a boat owner who has room and is taking divers out, you might ask if they have room for more. If there are enough interested people to charter a dive boat, that might be an option. If you want to take the public ferry over and shore dive, that's cool too... the wreck of the 74 gun French ship-of-the-line Magnifique is right off Lovell's, but no one knows exactly where.
The bottom line is that we plan to get ourselves to the island, do some diving, meet some new friends, have a great time, cook some delicious food, have a fire on the beach, and camp out. Figuring out the logistics is part of the fun... it's a semi-organized trip at best.