Lets see, well, the kayaking itself doesn't take that long maybe 30 minutes or so, but that depends on how experienced you and your group are. Paddling *out* to De Palm is fairly easy, though in a few areas the waves were pretty challenging and i *almost* tipped out of the yak. Remember you have to get back in! The instructions and such takes a while.
I don't remember what tour company it was, but they picked us up by bus and took us to their facilites, outfitted us with paddles, boats, life jackets and instructed us. The guides can take your "stuff" over to De Palm for you. Let them. If you tip out and don't have dry bags your stuff gets wet.
On the excursion we took, all of De Palm, facilities and lunch was included, however, if you want to snuba or some other such stuff, thats extra. Dh and I LOVE snorkling so we brought our own gear and it was such a trill to swim with the huge beatiful parrot fish and other tropical fish. We layed in the sun, went down the water slides a few times, just to say we did it and had a terrrific lunch.
THen its time to kayak back.....against the trade winds. This was VERY challenging. I'm 5'4", weigh 135 and i do snorkle, cycle, kayak and go to the gym, so i think i'm in pretty decent shape, even if it was the end of a New England winter. I *did* paddle myself all the way back only finishinig second behind my DH (i know its not a race) however it is challenging on the arms. Oh, and DH turned sideways to the winds to look back at how i was doing, got his boat on top of one of those waves and out he went!
The only thing we would want to do different is spend more time on De Palm. We both did enjoy the kayaking in the ocean very much.
HTH