I went to Caulker on the Winnie Estelle, a converted fishing boat; they took out the equipment and installed industrial sized RUM PUNCH COOLERS. Snorkled twice and pet the sharks, we only spent about 2 hours on the island, but I would wager if you needed to stay you could do that for pretty cheap. Caulker is maybe a 15 minute stroll long so...I doubt you'd really need to stay overnight. I loved the place, if Ambergris is mellow, Caulker is comatose--in a good way :-]. Can you tell I'm at work on a Saturday and prosrastinating?