Troy,
When are your going to Belize? I will be there in June 2014. As stated on the board, lots of threads about this. One mans horrible is another mans fantastic. So you will get it is great and you will hear it sucks. I have never dove the Blue Hole, and don't plan to. I have 580+ dives and for me personally, doing this dive on an AL80 is not something I want to do. From what I hear it is essentially a tourist trap and is vastly over hyped. The dive planning of the dive operators is also a bit, ummm interesting.
Visit
www.belieadventure.ca/great-blue-hole for one divers report. and read the medical advice about other divers who did the dive to their determent.
Go to YOUTUBE and search for Belize Blue Hole SCUBA Dives - several to choose from. I found it interesting that in most of the videos, the fish pretty much disappeared after 60 feet, leaving the deep dive to be primarily to see stalactites.
Do not ever do a TRUST ME DIVE. That is where you rely on someone else's skills to get you there and back because the dive exceeds your training, skill and competence. During the dive briefing you may (I am told will) hear the DM tell you your dive computer "may" show deco. The dive profile they outline is more than may, how about likely! I am also told the real sights (if you call looking at rocks real sights) are below 150 feet).
I see you plan to:
A: have 35 dives before you go
B: Have completed the deep diver course (note that is not a DECO diver course).
That said, how is your air consumption and Surface Air Consumption Rate (SAC)? How is your buoyancy? Can you maintain your desired depth while remaining still? Can you ascend consistently from what ever depth at 30 feet per minute or less?
See below for EXAMPLE dive profiles for the BH. The first at a SAC of 1.0 and the second at 0.65. NOTE, EXAMPLES FOR DISCUSSION ONLY, NOT FOR USE IN DIVE PLANNING. Your actual SAC rate is most likely different from the examples and will vary from dive to dive based on conditions, current, temp, hydration, physical conditioning, rest and mental state. All of the below dive plans make the following assumptions:
1. NO DIVES in PREVIOUS 24 HOURS.
2. Decent rate of 40 feet per minute (I tend to drift down slowly, even slower than that)
3. AL S80 tank filled to 3000 PSI (right, like that is likely to happen on the dive boat).
4. Ascent rate of 30 feet per minute
5. Actual Bottom Time of 7 minutes at depth of 135 feet
In reading my Belize dive operators information the BH will take 2-2.5 hours to get there and cost $355.00 for Blue Hole/Lighthouse (Blue Hole Park Fee NOT included).
Now if you will look carefully at these dive profiles, you will note that both dives are DECO dives, and that running out of AIR before you complete all of the deco is very likely. Nope, too much great diving in Belize much closer to my resort for me to waste that much money on what is for me high risk diving.
YOU AND YOU ALONE ARE RESPONSIBLE FOR YOUR SAFETY AND DIVE DECISIONS. Oh, and just in case where is the nearest decompression chamber in relation to the BH?. Have you joined Divers Alert Network(DAN) and purchased Dive Insurance (or obtained a dive insurance from somewhere)?