How do divers not realize their air isn't on?

[Gareth J]

WOW. I've never heard of that. This is sort of off-topic, but how do they equalize that fast? And is the reason for getting down that quickly is that it's a drift dive with a really strong current at the top?

There are dive sites where due to tide, a negative entry is required.
The Tabarka in Scapa Flow is well known as a site that requires a negative entry if you expect to hit the wreck. It is one of the Churchill Barriers and subject to significant tidal flow with short periods of slack.
It is not unusual for some divers to miss the wreck due to their failure to descend quickly into its shelter.

See the link for divers dropping on to the Tabarka.

 

[Rred]

It is not just a binary question of "on or off?" A friend and buddy of mine had a problem once. I found out because I noticed my jaws were aching and apparently my custom-bite-fit regulator had been ripped out of them. While I was thinking about this (in about 45') I was getting out my Octopus (kept in pocket, not on a leash with a sand plug) and turning to see what was over my shoulder.
A buddyfish, panting on my regulator. Who eventually signed out of air to me.

Apparently that problem hadn't existing until depth, because their air WAS ON, but as several folks swore, their class had been taught to just turn the valve on 1/4 turn. Leaving the pressure totally inadequate at depth, either to breath or inflate the BC.

Partly my fault, if you follow the "cross check each others equipment" school. But, my class hadn't been taught that, and we weren't parachutists. I still don't like anyone else poking fingers near my gear, including the tank valve.

And as that other poster, I put those (horribly wrong named!) Vindicator valve handles on my tanks, because they make it Real Damned Hard to not notice if the valve is on or off. One extra confirmation, that even my buddy can see, without touching the tank.

 

[M DeM]

There are dive sites where due to tide, a negative entry is required.
The Tabarka in Scapa Flow is well known as a site that requires a negative entry if you expect to hit the wreck. It is one of the Churchill Barriers and subject to significant tidal flow with short periods of slack.
It is not unusual for some divers to miss the wreck due to their failure to descend quickly into its shelter.

See the link for divers dropping on to the Tabarka.

HOLY CRAP IVE NEVER SEEN THAT! They just..... disappear. Wild. Thanks for the videos.

I’m learning so much here. Granted, so much stuff that I never ever try in my life. Like a negative entry. But still so cool.

 

[RyanT]

HOLY CRAP IVE NEVER SEEN THAT! They just..... disappear. Wild. Thanks for the videos.

In Florida we call it a hot drop...pretty common for a lot of the deeper wrecks where the current is often ripping. The first time you do it, it can seem really scary. You learn pretty quickly though that if done right, it's actually a really pleasant way to hit the wreck. It sure beats fighting the current on a line.

 

[Soloist]

HOLY CRAP IVE NEVER SEEN THAT! They just..... disappear. Wild.

A negative entry is certainly nothing to fear. It’s actually very efficient and dramatically increases your chances of seeing eagle rays and other marine life before the hordes of other divers frighten them away. This video begins with a negative entry from a diver’s perspective for what it is worth.

Video Cozumel April 2018 with Tres Pelicanos (3P’s)

 

[M DeM]

A negative entry is certainly nothing to fear. It’s actually very efficient and dramatically increases your chances of seeing eagle rays and other marine life before the hordes of other divers frighten them away. This video begins with a negative entry from a diver’s perspective for what it is worth.

Video Cozumel April 2018 with Tres Pelicanos (3P’s)

OKAY - NOW I'VE GOT QUESTIONS!

First... I can't believe how beautiful that video is.. Were you using a long lens? How did you get so freaking close to those moray eels? And the footage is so steady! And why is that fish practically riding that ray?

That's amazing footage. Really wonderful. And "Demon Spawn" is hilarious.

 

[Soloist]

OKAY - NOW I'VE GOT QUESTIONS!

First... I can't believe how beautiful that video is.. Were you using a long lens? How did you get so freaking close to those moray eels? And the footage is so steady! And why is that fish practically riding that ray?

That's amazing footage. Really wonderful. And "Demon Spawn" is hilarious.

Thanks! I don’t want to hijack the thread going off on a tangent blathering about cameras. Maybe you can repost your questions on the thread with the video, but the short answer is most of that was recorded with a GoPro4.