Great. Blue. Hole.

March 29, 2010 3:16 AM

"Surrounded by darker, deeper ocean waters, coral atolls often glow in vibrant hues of turquoise, teal, peacock blue, or aquamarine. Belize's Lighthouse Reef Atoll fits this description, with its shallow waters covering light-colored coral: the combination of water and pale corals creates varying shades of blue-green. Within this small sea of light colors, however, lies a giant circle of deep blue. Roughly 300 meters (1,000 feet) across and 125 meters (400 feet) deep, the feature is known as the Great Blue Hole." (Massive NASA image of the atoll).

"The Great Blue Hole — the world’s largest blue hole — is ... a small atoll 60 miles (96 kilometers) east of the Belize mainland. The hole is near perfectly circular in shape ..."

Unfortunately high-resolution images are few; this one is so-so.

Also, previously at AskMeFi.

posted by bwg (24 comments total)

Throw a little orange into that teal and you might have a hit.
posted by twoleftfeet at 3:28 AM on March 29, 2010 [6 favorites]

Throw a little orange into that teal and you might have a hit.

That's a FPP in its own right.
posted by Blazecock Pileon at 3:40 AM on March 29, 2010

I love this. Thank you for sharing it!
posted by Joey Michaels at 3:41 AM on March 29, 2010

It's a belly button. Dive deep enough and you find fluff.
posted by dowcrag at 3:44 AM on March 29, 2010 [2 favorites]

Dive deep enough and you find fluff.

Not 'arf...
posted by sodium lights the horizon at 3:47 AM on March 29, 2010 [2 favorites]

Climb inside my belly button...
posted by Evilspork at 3:56 AM on March 29, 2010

It's a belly button. Dive deep enough and you find fluff.

Or the keys to your truck.
posted by NoMich at 5:44 AM on March 29, 2010

Rather have a belly button than a Goatsee going on.
posted by stormpooper at 6:05 AM on March 29, 2010

This is pretty high on my list of places I want to see. Maybe it's time to take that refresher course.
posted by bashos_frog at 6:10 AM on March 29, 2010

This just creeps me out.
posted by Solon and Thanks at 6:16 AM on March 29, 2010

Hello nightmares!
posted by odinsdream at 6:31 AM on March 29, 2010

MetaFilter: great blue hole
posted by bwg at 6:44 AM on March 29, 2010 [3 favorites]

That's a FPP in its own right.

Indeed
posted by jedicus at 6:44 AM on March 29, 2010

Nova did an episode on blue hole diving, where they visited several similar formations in the Bahamas. None are as impressive from space, but all look spectacular from inside.
posted by Hoenikker at 6:45 AM on March 29, 2010 [1 favorite]

Some photos on Flickr.
posted by msittig at 8:46 AM on March 29, 2010

You might not be thinking it, but don't tell me you wouldn't wanna see it (from a distance).
posted by rahnefan at 9:39 AM on March 29, 2010

I was very close to signing up for a dive trip there, from Caye Caulker, but chickened out at the last minute -- it was an overnight boat trip and it wasn't cheap either. I knew I'd come to regret my lameness.
posted by muckster at 12:02 PM on March 29, 2010

I don't understand this image from the third link. It looks like the guy in the photo is in a cave, but only submerged up to his thighs. Where is he and what does that place have to do with the blue hole?
posted by invitapriore at 12:53 PM on March 29, 2010

The thing about diving the Blue Hole, at least recreationally, is that it's simultaneously a bit nerve-wracking and quite dull.

Technical divers, like the writer of the third link, have special equipment and training so that they can go deep and stay down longer (they actually have to stay down longer to do decompression stops). The maximum depth for recreational scuba divers is 130 feet for safety reasons, and at that depth you can only stay for a few minutes. At our pre-dive briefing the divemasters were very clear that if one of us wandered off and went below the 130-foot threshold, they would not come to get us and put their own lives at risk. Actually our divemasters were very nice, very dedicated people and I suspect they would have tried to help if there'd been a real problem, but their point was that we couldn't count on them to protect us from our own stupidity. So there's a very narrow time and depth window to explore the Blue Hole -- I was in the water for 32 minutes, and at least half of that was at the shallower depths on the rim of the sinkhole, not the sinkhole itself. (Your average recreational dive is 40+ minutes.)

Occasional sharks aside, there's no life in the sinkhole itself other than the algae/seaweed growing on the rock. It's almost featureless apart from the (very cool) stalactites, which makes it hard to judge how fast you're dropping, and there aren't a lot of those until you get quite deep anyway -- say a hundred feet, give or take. Except once you get down there it's chilly, dark, and the visibility is terrible. The photos in the second Flickr set linked above show the murkiness pretty well, and remember that dive photographers bring powerful lighting with them so that all their subjects don't come out dim and gray/brownish. Imagine photos like this or this without the strobe lights, and you'll start to get an idea. So rather than enjoying the scenery you're constantly tracking your barely-visible dive buddies and watching your depth gauge (and in my case trying not to get snagged on a stalactite) because if you lose track of either, you could be in serious, serious trouble.

People dive the Great Blue Hole more because of the minor bragging rights than anything else. Our divemasters even told us that it was kind of a boring dive and they were only taking us so we could say we'd done it; one of us was making his second dive there and he told me before we went in that he was only going because it was better than sitting on the boat waiting for us to come back. To put it more charitably, it's one of those dives that has more value in having done it and having the experience to talk about than because it's an interesting dive in and of itself.

Which isn't to say that I didn't enjoy myself, but given the choice between diving the Blue Hole again or revisiting any of the other twelve dive sites I visited in Belize, I'd choose the other site.
posted by bettafish at 2:34 PM on March 29, 2010 [2 favorites]

Yeah, I'd heard some of that, bettafish, which is why we stayed around Caulker. The diving and snorkeling there were pretty fantastic, too -- but no bragging rights!
posted by muckster at 9:51 PM on March 29, 2010

My father had dive buddies who knew Cousteau way back in the day who claimed Cousteau once dynamited a pass in the reef so the Calypso could pass through into the Blue Hole. I don't know if it is true but that is what he said when Lighthouse Reef came up in conversation. Back when it was British Honduras, not yet Belize.
posted by Mei's lost sandal at 11:15 PM on March 29, 2010

Bettafish's comment makes me feel kinda shitty since I'm going to Belize in two days and one of the things I'm doing is diving the Blue Hole. I'm definitely a recreational diver. I only got my certifcation yesterday. Oh well.
posted by runcibleshaw at 1:38 AM on March 30, 2010

Oh hey! That last link is me. Neat.
posted by runcibleshaw at 1:39 AM on March 30, 2010

Runcible, I don't think it's a bad dive, just overhyped. Screw what I say, though, go enjoy yourself!
posted by bettafish at 5:52 PM on March 30, 2010