Anybody have waypoints for passes through the Belize barrier reef?

[GrowleyMonster]

Thinking about sailing New Orleans to Belize around the end of April. I have been in through English Caye Channel and I have motored a shallow draft skiff through the pass at the north end of Caye Caulker, but I am particularly interested in San Pedro Pass, and any other passes that anyone here is familiar with. I know about the yellow bouy, and I know it isn't there anymore, but what can anyone tell me about the red roof that I am supposed to line up on at 318 degrees with the absent yellow bouy? And is that 318 true or magnetic? Trying to piece these little bits of info and hearsay into something I can correlate with my charts and Google Earth and end up with something useful. My draft is 4'7". Good waypoints would be particularly appreciated, as well as any better descriptions of landmarks and ranges. I want to check in at San Pedro and chill out there and at Caye Caulker for a week or two before hitting the mainland and visiting family I have there. Thanks for any help anybody can give!