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I started this thread to describe a very infamous dive; the Blue Hole's arch. My objective is to put a scenario to people willing to do it.
The Blue Hole is literally a hole in the reef that is around 56 meters (184 feet) wide and its max depth is around 120 meters (394 feet). On the southern side of the site, there is a saddle (eroded lip) located at 7 meters (23 feet). The most important feature of the Blue Hole is the archway, which is located at 56 meters (184 feet) and exits into the bottomless open sea.
Unexperienced recreational divers may deal with this dive as an ordinary cave dive. One could just think it's pretty simple; drop to 56 meters (184 feet), cross the arch, then ascend to the saddle at 7 meters (23 feet) and re-enter the Blue Hole.
Unfortunately this is not true. Here's what you should take into consideration:
1. First of all, you have to correctly locate the arch. The arch is not directly below the saddle. It is on the eastern side of the site not the southern one.
2. You should drop down at the correct place because the reef curves around and you many not be able to see the arch. Searching for the arch at depth is not a brilliant idea.
3. One way to locate the arch is to drop down to 30 meters (100 feet) at the western side of the Blue Hole. You'll find a sandy gully. Following this sandy gully will finally lead you to the arch, but at 75 meters (247 feet). Not a brilliant idea either.
4. A blue glow becomes visible at 52 meters (171 feet). This is not the proper depth to cross the arch at. You have to desend other 4 - 5 meters (13 - 17 feet) to seamlessly cross the arch because the roof is actually located at 55 meters (181 feet).
5. Now you're trying to cross this 26 meters (86 feet) long, 25 meters (82 feet) width hole. If you're not 100% sure of your buoyancy at depth, don't do it.
If you can't cross these 26 meters (86 feet) in a horizontal path, you'll either hit the arch's roof or go much deeper than you should.
6. Depending on sea conditions, you may experience poor visibility and poor light conditions so take a torch with you.
7. Now the most dangerous part, the strong downwards currents that could be experienced at the exit of the arch. More fining means more gas consumption and more stress. Returning back means exactly the same plus more decompression.
8. Make an if - then scenario and follow it. For example:
A. If I consume more than 20% of my gas before locating the arch, I won't enter.
B. If I face strong downwards currents, I won't panic and I'll alter my fining (dolphin kicks instead of frog or flutter, for example) to safetly cross the arch.
9. Now that you crossed the arch, you need to do several mandatory decompression stops. You need to be sure of your capability of carrying over controlled stops. It is highly advisable to plan the dive using computer software before execution. Write your plan on a slate and use a dive computer as well. Never attempt to do this dive without a dive computer.
Finally, a personal proverb I always use; risk doesn't kill, stubbornness do. Don't do it unless you know you're capable.
Asser Salama
The Blue Hole is literally a hole in the reef that is around 56 meters (184 feet) wide and its max depth is around 120 meters (394 feet). On the southern side of the site, there is a saddle (eroded lip) located at 7 meters (23 feet). The most important feature of the Blue Hole is the archway, which is located at 56 meters (184 feet) and exits into the bottomless open sea.
Unexperienced recreational divers may deal with this dive as an ordinary cave dive. One could just think it's pretty simple; drop to 56 meters (184 feet), cross the arch, then ascend to the saddle at 7 meters (23 feet) and re-enter the Blue Hole.
Unfortunately this is not true. Here's what you should take into consideration:
1. First of all, you have to correctly locate the arch. The arch is not directly below the saddle. It is on the eastern side of the site not the southern one.
2. You should drop down at the correct place because the reef curves around and you many not be able to see the arch. Searching for the arch at depth is not a brilliant idea.
3. One way to locate the arch is to drop down to 30 meters (100 feet) at the western side of the Blue Hole. You'll find a sandy gully. Following this sandy gully will finally lead you to the arch, but at 75 meters (247 feet). Not a brilliant idea either.
4. A blue glow becomes visible at 52 meters (171 feet). This is not the proper depth to cross the arch at. You have to desend other 4 - 5 meters (13 - 17 feet) to seamlessly cross the arch because the roof is actually located at 55 meters (181 feet).
5. Now you're trying to cross this 26 meters (86 feet) long, 25 meters (82 feet) width hole. If you're not 100% sure of your buoyancy at depth, don't do it.
If you can't cross these 26 meters (86 feet) in a horizontal path, you'll either hit the arch's roof or go much deeper than you should.
6. Depending on sea conditions, you may experience poor visibility and poor light conditions so take a torch with you.
7. Now the most dangerous part, the strong downwards currents that could be experienced at the exit of the arch. More fining means more gas consumption and more stress. Returning back means exactly the same plus more decompression.
8. Make an if - then scenario and follow it. For example:
A. If I consume more than 20% of my gas before locating the arch, I won't enter.
B. If I face strong downwards currents, I won't panic and I'll alter my fining (dolphin kicks instead of frog or flutter, for example) to safetly cross the arch.
9. Now that you crossed the arch, you need to do several mandatory decompression stops. You need to be sure of your capability of carrying over controlled stops. It is highly advisable to plan the dive using computer software before execution. Write your plan on a slate and use a dive computer as well. Never attempt to do this dive without a dive computer.
Finally, a personal proverb I always use; risk doesn't kill, stubbornness do. Don't do it unless you know you're capable.
Asser Salama
