Blue Hole Dive Planning

[peterbj7]

Not so. At great expense I set up a blending station that was capable of producing any mix by continuous flow, and in particular any mix up to 40% at effectively the same rate as air. When I closed my operation last year I sold that setup to AquaDives. They now have the only such pumping station south of the US with the sole exception of Playa del Carmen (and that doesn't have the same capacity).

 

[Texasdivechick]

I was told by a local diver/ instructor (Elbert) that they no longer blend custom gases. He was also the person who gave me the info on Blue Hole dive profiles. Nice guy. We had an interesting conversation while hanging out at Island Perk one afternoon last week, which I also discovered was going out of business. What a shame.

 

[peterbj7]

I shouldn't believe all you're told by people who may have their own axe to grind. Ask the principals.

Island Perk isn't going out of business, but relocating as their landlady has decided she doesn't want to receive rent any more. They'll shortly be opening just a few yards away.

 

[Texasdivechick]

I'm glad to hear that Island Perk will still be open for business. They had the best coffee on the island. I'm also glad that I didn't dive the Blue Hole. I know it's a log-book dive but I just don't feel as though I have enough deep diving experience to undertake a 140' dive. I've only been below 100' about 10 times, and I was noticeably narced about half of those. I didn't do anything stupid. I just didn't like the boozy feeling. I think I'll wait until I am more comfortable with deep diving and in a group of dive buddies that I know and trust. Overly cautious?

 

[Hawkwood]

I agree with those who said the Blue Hole is a been there, done that kind of dive. My wife and I dove it twice last summer while staying for two weeks at Turneffe Island Lodge. The Lodge (now Turneffe Island Resort) goes to the Blue Hole on Tuesdays, then stays in the area and dives the Aquarium and Long Caye Wall, both of which are fantastic dives, before returning to the resort.
.............

I agree, the second dives of the day were fantastic and not to be missed. When we went out with TIL a few weeks ago, half of the group went deep and the other half stayed up (I stayed up). It was interesting to see how the split worked. The least experienced divers went deep. To be very honest, after the dive briefing I couldn't see what the point was of us doing the dive. I was surprised to find out I was not alone in my sentiments.

Even staying shallow was nothing to write home about. Next time we go we figure we'd stay topside and just snorkel.

Gee, I think this is the first "negative" positng I've done.

 

[cyberdyver]

Not so. At great expense I set up a blending station that was capable of producing any mix by continuous flow, and in particular any mix up to 40% at effectively the same rate as air. When I closed my operation last year I sold that setup to AquaDives. They now have the only such pumping station south of the US with the sole exception of Playa del Carmen (and that doesn't have the same capacity).

I was doing custom blends for myself and guests using the "Stik" back in my guiding days but then again, I was not at Ambergris.

 

[Dan Weidert]

The hole is stated at 135'...MOD of 32% is 130'. So don't touch the sand, stay off the bottom. (good idea anyway) Will extend bottom time or used as reg. air will give a cushion of sorts to the OP, who has stated that getting so close to NDL makes them uneasy to begin with. But if nitrox is not (can't) used in this dive then it's a mute point.

If you accept MOD as a partial pressure of O2 of 1.4 ATA then
MOD = ((1.4/EANX) - 1)*33
MOD = ((1.4/.32) -1)*33
MOD = (3.375)*33
MOD = 111 feet

If you accept Contingency Depth (what you could go to in an emergency) as a partial pressure of O2 of 1.6 ATA then
Contin Depth = ((1.6/EANX)-1)*33
Contin Depth = ((1.6/.32)-1)*33
Contin Depth = 132 feet

A "Slightrox" blend of .25 would give you a MOD of 152 feet.

By the way, if you are good with Excel, simply plug the above formula's in to a couple of cells, use the dohickey (the little plus sign) to copy into all of the other cells and VIOLA, you have a handy table for MOD and contingency depth for any blend you end up with.

Dan

 

[peterbj7]

Remembering to plan for an actual dived depth of 150ft, with a contingency according to your accuracy of buoyancy control. I used to provide 28% for the dive, but in all honesty I didn't use it myself. Much simpler just to use air. But nitrox on the following two wall dives is a good idea, or with decent consumption and long dives you'll be battling available bottom time. I've had 1hr 10mins on the HMC wall dive and 1hr 20mins on the LC wall dive, and without nitrox neither would have been remotely possible. 32% will do, though 36% can be used on the final dive if available.

My setup was much more complex and expensive than a simple stick. It was quite capable of filling over 30 tanks/hour of 32%, rather less with 36%. I had a storage bank of over 30 large storage cylinders. All now sold.