Diver Storytime - The sinking diver

[PhatD1ver]

Well, I went off on a thought with my other story and forgot the one I wanted to share.. the original thought I was working off with my review of my military training is that a large part of flight safety is reviewing flight safety incidents and accidents. Obviously, we like to review the incidents more, because people don't usually die or aircraft don't get destroyed. Accidents, they are BAD.

So, me being me, I thought in my limited experience, I'd share a little 'incident' that I had in the past few weeks as I've been learning to be a better diver.

The setting is this. I'm home in the US. I've purchased a dry suit online (off scubaboard.com) and my luck is amazing, this thing fits like a glove. Seals are awesome. I get to the US and have an instructor set up the day before my declared 'dive day' with my family members at Catalina to start my dry suit training. Prior to leaving China, I get my knowledge development information, watch my videos, talk to my local instructor a lot, and pass the knowledge reviews. On landing in the US, I get my suit out, try it on, and then go see the LDS near my Utah home for some zipper wax. I pack everything up, and next morning, I'm in LA. By afternoon, I'm in the dive shop, and my new instructor gives me a full follow up on the dry suit, care, maintenance, seal care, zipper care, inspection, cleaning, etc. Then we don the monster, get our gear, and spend a little under an hour with me performing various tasks, purposely getting light in the feet, releasing air, adjusting the valve, and learning to balance the buoyancy of the dry suit with the BCD still primary, enough air to be warm and still use my BCD as it is designed. Everything does well, he's pleased at how I pick it up.

Dive day is just as good. We spend the first dive following up on the pool training. Changing depth, adjusting for water temp, relearning a little buoyancy and trim... but the dive goes very well, as do the following two dives.. It's a very successful day diving with my family, and the instructor enjoyed it because he didn't have to do anything more than put me thru a few skills along the way. WIN WIN.

Now, it's two days later, I've got a bug to go dive again, problem is, I haven't got a buddy. But I've spent weeks reading about different sites along the Palos Verde coastline, and I determine to take my gear and head north from San Pedro to at least Redondo (where I'm almost guaranteed to find someone on a flat day like this to get wet with). I end up stopping at Old Marineland, now called Terranea (a very expensive resort) and find a guy dragging gear across the lot... he's waiting for a couple other guys, and calls and asks if I can join them. With me, we make a perfect six. Works for them, so while he waits, I get my stuff and start the march down to the beach.

As it turned out, I waited for nearly 1 1/2 hours, they finally told me they were on their way down, and knowing it takes a little time to get in to my dry suit, I started prepping and donned it, but they were still lagging... so rather than roast in the sun, I slip into the rocky shore with relatively calm surf conditions, and just soak the suit down to stay cool. A few minutes later, the guys arrive and are quick to put their gear on and get in... I get my BCD and fins and walk out, inflating just before I turn to catch the back side of a small set of waves now coming in... as I'm sitting there trying to put my fins on, I realize I am not floating, but sinking. Looking down I see I'm probably 6-10 feet above the rocky bottom. And I inflate again, and again, by the time I can reach down to try putting on a fin, I'm already up to my ears.

So, I have no idea what's happening, I inflate again and test my dump port, my buddy says it's fine, my shoulder port is fine. But everytime I inflate, 30 seconds later I'm over my head in the water. So, I now get to use my drysuit for enough buoyancy to stay with my head above water.

I decide to let them go, and now start a nasty swim to shore as the surf has picked up, and the rocks are a major pain.. it's a lot of work to get back, and even more to get me and my 25# of weight and tank out of the water, and up the rocks... As I rest, the sun takes over and tells me my day is over, I can't troubleshoot my problem in my drysuit, and they are waiting 50meters out to see if I'm coming back.

I wave them off and start carrying my stuff up the beach front to my mat and bags. After I've removed my drysuit, I get back to my BCD and start trying to figure out what is going on. I test it and now it won't leak any air, it just sits there actually expanding as the air heats inside it's black cover. But then what I find is a little chilling.

You see, this is a NEW BCD with one pool session and three dives on it. I'm a little miffed it might be leaking air, and so I'm checking seams, all over. What I finally find is that this nifty little BCD has a 'jet dump' where you don't have to raise the inflator above your head to you can just pull and dump air from your shoulder... what was wrong was that the little cap that screws on the top of the inflator at the shoulder had become loose and was barely held on by a single thread and less than half a twist of the cap. This caused the o-ring at the end of the pull assembly to let air leak past, and of course, in water, with the pressure pushing against the bag, it's pushing air past the valve, and when my buddy looked at it, he thought it was me purging it.

However, the long story was that this could have been a bad day for me, granted I had a drysuit to inflate and maintain buoyancy, but the thought in my mind was what if I'd swam out to 20 feet and the little cap popped off, immediately dumping me with my weights to the bottom (I might have caught it with my drysuit, but that's a scary proposition for a new drysuit diver).

I spent the day at Catalina being bummed about this new BCD supposedly not having the little shoulder dump like many others on the right shoulder, with the little pull handle on the right breast. It actually was making me mad I'd paid so much for it and it lacked that function.

So, what have we learned my friends from our storytime lesson?

1) If you are a new diver, and you have purchased equipment, go over it with someone in the know. Understand how every part of it works.
2) Check your equipment, make sure all seals, o-rings, and valves are working and seal properly (This would probably happen if you follow #1, but an example in a book on dive stories indicates that might not be true. In fact it was this story that finally clued me into the fact that I had a 'jet dump' not just an open cap)
3) Know the procedure you will follow in the event you lose your buoyancy at the surface.

I was lucky, this was a shore dive, I could swim back in... if this had been off the boat the day before in 60 feet of water, and the cap had popped off the inflator when I made my entry, I could have been riding a one way ticket down. Maybe I'd have had my wits about me to inflate my dry suit, but from the boat entry point, I would have been the only one to save me, because my instructor was already in the water and had moved toward the anchor point.

Hope this prevents someone else from a bad day. Cheers

PhatD1ver

 

[undrwater]

Replace the shoulder dump with a standard elbow and eliminate that failure point.

Realize you could have dumped your weights and likely been fine. Dump your gear if not.

To bad you missed a dive at OML.

 

[Storker]

This is why I strongly prefer a drysuit when I don't have a hard bottom at rec depths below me. Redundant buoyancy rules!

The story is also a good argument for doing a proper pre-dive check. One of the things I always do is to inflate my BCD until the dump valve "farts", making sure it at least holds air topside. Either during "B" (BCD) or during "A" (air), usually it's with "A" (check SPG, breathe primary, breathe backup, fill BCD, all while monitoring my SPG).

Sometimes, the topside check isn't enough, though. On one of my recent dives, my buddy's BCD seemed OK topside, but it started leaking from the shoulder dump valve at around 20m depth. It was a wall dive without hard bottom below. Luckily, we were diving dry, so he could use his DS for buoyancy. We aborted the dive anyway, because we didn't have redundant buoyancy any more. I've dived with a leaking BCD, just using my DS for buoyancy control, but that was over a hard bottom at 20m, the sea was calm and the waters were sheltered.

Realize you could have dumped your weights and likely been fine.

This can't be said too often. Too many divers have surfaced, failed to ensure positive buoyancy, not dumped their weights and drowned. Lead is cheap, my life is precious.

 

[DukeAMO]

I've also had a BCD that would only leak under water. Sneaky little buggers. In my case, there was a small hole in the bladder. On the surface, there wasn't enough pressure to force air out of it quickly enough to notice. Under water, you could see a steady stream of small bubbles. I was able to dive anyway because it was a slow leak in a shallow lake, but I was still miffed. I missed one of two dives while trying to troubleshoot the problem.

The other thing that annoyed me is that the BCD had just come back from servicing and its annual inspection, and that was my first dive! We sent the bladder back to the manufacturer for a new one, because it was still under warranty.

 

[mrdre]

.... but the thought in my mind was what if I'd swam out to 20 feet and the little cap popped off, immediately dumping me with my weights to the bottom (I might have caught it with my drysuit, but that's a scary proposition for a new drysuit diver).....

Mmm... wait.. are you sure you are not overweight? With empty BCD and drysuit you should have been somewhat neutral on the surface.

 

[Storker]

With empty BCD and drysuit you should have been somewhat neutral on the surface.

IME, if I'm neutral on the surface with a full tank, I'm going to be too light towards the end of the dive. The buoyancy swing of my standard tank (steel 10L 300 bar) from full to 50 bar pressure is around 3kg, which means that if I want to be able to hold my safety stop without too much problems, I need to be at least 3kg negative at the start of my dive. For other tank sizes, the buoyancy swing will of course be different.

I only dive wet while on vacation, and all my home diving is dry, so I'm definitely more experienced with drysuits than with wetsuits. I believe that this "neutral at the surface" thing may be more appropriate if diving wet, since neoprene compresses and loses buoyancy from the surface down to safety stop depth. Trilam doesn't, so if my DS is thoroughly vented, I don't experience much of a buoyancy swing during my last ascent. OTOH, if I'm weighted to have both an empty BCD and an empty suit, I'm so shrink-wrapped that I start having problems reaching my chest D-rings, so I prefer a litte "overweighting" to be able to keep a little comfort air in my undergarments.

Also, if the water is cold, a little extra weight will accommodate a little extra air in the undergarments, which translates to better insulation against the cold.

For me, ideal weighting in a DS allows me to hold my safety stop without corking, with less than 50 bar left, while still having enough air in the suit that freedom of movement isn't restricted and my undergarments are able to provide insulation against the cold. If I'm weighted that way, I'm definitely negative at the surface before descending, with my suit burped and my shoulder valve open.

 

[mrdre]

IME, if I'm neutral on the surface with a full tank, I'm going to be too light towards the end of the dive. The buoyancy swing of my standard tank (steel 10L 300 bar) from full to 50 bar pressure is around 3kg, which means that if I want to be able to hold my safety stop without too much problems, I need to be at least 3kg negative at the start of my dive. For other tank sizes, the buoyancy swing will of course be different.

I only dive wet while on vacation, and all my home diving is dry, so I'm definitely more experienced with drysuits than with wetsuits. I believe that this "neutral at the surface" thing may be more appropriate if diving wet, since neoprene compresses and loses buoyancy from the surface down to safety stop depth. Trilam doesn't, so if my DS is thoroughly vented, I don't experience much of a buoyancy swing during my last ascent. OTOH, if I'm weighted to have both an empty BCD and an empty suit, I'm so shrink-wrapped that I start having problems reaching my chest D-rings, so I prefer a litte "overweighting" to be able to keep a little comfort air in my undergarments.

Also, if the water is cold, a little extra weight will accommodate a little extra air in the undergarments, which translates to better insulation against the cold.

For me, ideal weighting in a DS allows me to hold my safety stop without corking, with less than 50 bar left, while still having enough air in the suit that freedom of movement isn't restricted and my undergarments are able to provide insulation against the cold. If I'm weighted that way, I'm definitely negative at the surface before descending, with my suit burped and my shoulder valve open.

Well, that's why I said "somewhat" neutral. I'm usually 1-2kg (3-4f pounds) negative on the surface at the beginning in drysuit. With my HP 100/120 steels it's good enough to be neutral at the end of the dive at 6 meters. But I have a feeling OP was way overweight.

 

[TSandM]

First off kudos to you for calling the dive with this malfunction, especially since you didn't understand what was wrong. Many times, it's tempting to proceed with a much-wanted dive in the face of a problem, but it takes some experience to know how you are going to manage a failure, and to be quite sure that the dive you have planned will be safe to execute in the face of that particular problem. New divers should just about always make their decisions in the conservative direction.

I will castigate your buddies, for allowing you to do your exit alone, though. In SoCal, entries and exits are often the most challenging parts of the dive, and certainly the places where one has a significant likelihood of injury. I realize you were just a "pick-up" buddy, but that's a buddy nonetheless, and in my book, someone should hat
ve accompanied you back.

A final thought -- Those of us who have been diving a while and diving a lot, have almost all gone to the simplest gear possible. Everything eventually breaks, and the more complicated gear is the more opportunities it has to do so, and the more complicated diagnosis is.

Given your background, you might find this interesting reading: Equipment Configuration | Global Underwater Explorers

 

[PhatD1ver]

A final thought -- Those of us who have been diving a while and diving a lot, have almost all gone to the simplest gear possible. Everything eventually breaks, and the more complicated gear is the more opportunities it has to do so, and the more complicated diagnosis is.

Given your background, you might find this interesting reading: Equipment Configuration | Global Underwater Explorers

That's the direction I hope to go eventually, 100 dives and 100# from now...