Edited: First stage not flooded

[Lizard Leg]

Background info: Aqualung Titan yoke first stage, HOG second stages, Pro Valve on a Worthington HP120 with Yoke insert installed. I've been using this setup for over 3 years like this.

Liveaboard trip this weekend. About a .75-1.0 knot surface current. I am a right below knee amputee and my dive prosthesis requires me "flipping a switch" once in the water to change the foot over from a walking position to a 70º plantar flexed diving position. With the current, I decided to sit on the edge of the entry and roll in - from 5 feet up since entering the water, flipping the foot and making my way back to retrieve the camera rig was a chore and a half with the current.​

First time worked great. No issues. Second time, night dive, 3-4's and current was still blowing. Hit the water slightly negative and nothing but water in my mouth. Purged, nothing but water again. Switched to my second and nothing but water. At the surface both breathed dry. Went back under, nothing but water.

Long story short, upon exiting the water the divemaster grabbed my tank valve at the top of the ladder to steady me and the yoke screw fell right out. The only thing any one can figure is that the DIN to yoke insert in the valve only allowed a few threads of the retaining screw to grab and the impact on the water either jarred it loose or stripped it, hence the water in the hoses.

Before having this first serviced or buying another first (DIN this time), I wanted to see if anyone else has had any experience with this.

 

[tursiops]

It sounds like the first stage was not actually seated correctly on the tank valve, in which case it would not hold pressure nor resist being used as a lifting point. Was your gas actually turned on? How do you know?

 

[Caveeagle]

Wow, that sounds like to bad situation. Glad you are ok. I assume you were breathing from the regs before you rolled into the water. ?? It seems odd that just the surface splash would be enough to dislodge everything. Any if the yoke connection came apart, you would have a massive gas leak that should have gotten the attention of everybody.

Was this a reg that had been converted to Yoke? Or using a yoke adapter?

Did you confirm the stripped threads on either the pro-valve or the yoke-screw? Something really had to be mismatched or out of whack for it to seal at the surface and then fail a few moments later.

 

[redacted]

What makes you believe the yoke screw was properly installed?

 

[Lizard Leg]

Gas was on and checked by at least 3 people before entering water - myself, buddy and divemaster at the exit. Buddy checks before entering water (breathing off of both regs watching SPG, etc.) no issues. I checked everything in the water (holding onto camera line). Gas was on and breathed fine above water with no issues. Inflator, purge, etc. all good. First exit from water, we took apart reg and checked diaphragm. No issues, breathed fine. Entered the water again with the same results nothing but water from both regs. Exited the water again and this time the retaining screw fell out when boarding the boat.

 

[Lizard Leg]

At no time was there any type of major gas leak - even after the retaining screw fell out - either above or below the water. Reg was in mouth, 2 breaths watching SPG (again) before splash in. Yoke insert in the valve has been there for 3.5 years. Replaced retaining screw with a borrowed one from crew and dove the rest of the weekend.

Yes it could have been a bad situation for someone not used to the water. I went in head first and went at least 5' down slightly negative with nothing but water. Throat was sore for a day or so. At the time, it was a logical answer, replaced, tested and continued diving. Now that I'm back on dry land time to analyze further.

 

[Lizard Leg]

First stage was straight from Aqualung. All hoses had been changed as well as primary and secondary regs. No modifications at all. Tank came with yoke insert in the Pro valve and it has never been removed.

 

[undrwater]

It's an interesting failure. Can you take a picture of the failed unit assembled? Maybe another close-up of the threads of the bad screw?

Kudos to you for how you handled yourself.

 

[undrwater]

Looking at it another way; if water got into the hoses on a charged tank, where did the gas go? It has to escape somewhere.

If three people checked your tank, perhaps one turned it off, and another loosened the yoke?

 

[Lizard Leg]

Screw is somewhere about 90' down right now. As to the gas being on/off - the gas was on, period. Breathed fine out of the water for 2-3 minutes each time. I hope we all know what a reg breathes like with your gas off/empty tank - it doesn't.

The breathing fine above water, 80% water below, and no leaks of any kind is why I am perplexed. I've blown a valve o-ring underwater before. Not something you forget. There were zero gas leaks anywhere and at the surface holding onto the camera line breathed as good as it ever did. Underwater, nope. Replaced the screw and did 3 more dives.

If the screw stripped or loosened, if the first got jarred out of position, etc. why the hell wasn't there a massive leak?