Negative Entries - A Bad Idea???

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In some of the drift diving I do we use negative entry. As has been stated through the posts this is not being over weighted, just going in with no air in the wing. We use it at times in the river as some of the sites are in the middle of the river and you need to get below the surface to get out of the way of boat traffic. As well if the boat is in the river and there is a ship coming the captains like to get the boat well out of the way of the ship and the divers down in a quick and efficient manner. This would not be used with divers that were not experience with doing this or were uncomfortable in the situation.
 
Negative entry and a quick decent is a ton of fun. The boat pulls up, the captain yells "Dive! Dive! Dive!" and everyone jumps in one after another in quick succession. Then the fast decent to the wreck. Oh no! Here it comes. Pull up. Air. Add more air. Oh no. Add more air. Whew.

It's like skydiving only underwater.
 
True story, really.

Cozumel, 2015. Regular dive guide for Devil' Throat is not available. Divers assured by the dive coordinator that the replacement guide knows what he is doing.

Divers prepare for negative high current entry. Replacement guide can't find the punta sur reef with Devils Throat. Boat goes inshore, offshore, up island, down island. Replacement dive guide jumps in with mask and is dragged on line behind the boat for 30 minutes looking for the reef. No reef. Diver asks guide if he has done this dive before. Replacement guide says no, this is my first time. YAFKM.

Boat moves to Palancar deep instead. Divers are still prepared for and execute negative entry dive.

60 feet down, two divers are observed clutching each other and plummeting down toward the reef. Divers hit the reef, coral goes everywhere. Divers are observed, startled and sharing air on the reef wondering what happened and what to do next.
 
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@divezonescuba This is clearly a story of an inexperienced DM and crew guiding divers that may not be overly experienced or confident in the situation. Of course hearing the DM was not sure what he/she was doing would make a lot of people lose confidence. It is unfortunate to hear these types of stories within the industry, but they are out there and many of us have had some experience with them first hand.
 
There is a bit more to the story.

The ooa diver was actually a very experienced diver himself which makes the whole incident that much more curious. If he had not had so much experience either he or perhaps both of them would be history.

The donating dive was also experienced but not as much with a deep cert.

According to the donating diver, the ooa diver just slammed into him and grabbed his alternate. A less experienced diver might have started fighting for the donors primary.

When I swam over to them, the ooa divers valve was loosely shut. Of course, there was then a leaking oring issue. However, that was mostly resolved. I would speculate that someone turned the valve closed rather than open. The valve was probably closed due to the common oring issue while we changed sites and then mistakenly turned the wrong way when we got to the second site. Based on what happened trying to find the original site, I would not be surprised if that was what happened.

After I opened the valve, the ooa diver initially refused to take back his primary. He eventually took it back and we actually completed the dive. I think most people would have been too freaked out at that time to continue on.

The ooa diver was actually a psychologist. We had an interesting discussion on the flight or fight instinct after the dive.

We successfully dove devils Throat the next day with the regular dive guide after having words with the dive operator.
 
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a negative descent isn't just about descending quickly, it useful for times when there is a surge or waves in which staying on the surface could potentially lead to issues like being slammed back into the boat during a current where the desired drop zone is small. Negative descents don't need excess weight to assist in the descent, just empty you BC/bladder
 
Negative entry and a quick decent is a ton of fun. The boat pulls up, the captain yells "Dive! Dive! Dive!" and everyone jumps in one after another in quick succession. Then the fast decent to the wreck. Oh no! Here it comes. Pull up. Air. Add more air. Oh no. Add more air. Whew.

It's like skydiving only underwater.

And equalize, equalize, equalize!
 
I've only done 1 or 2 negative descents in my short (~60 dives) diving career, and equalizing is the limiting factor in how fast I can get down. I'm pretty much holding my nose and puffing out the whole time.
 
I've only done 1 or 2 negative descents in my short (~60 dives) diving career, and equalizing is the limiting factor in how fast I can get down. I'm pretty much holding my nose and puffing out the whole time.

So the rest were positive descents? How do you manage that? ;-)
 
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