Aborted Plan At Langley Marina

[sambolino44]

I don't know how "near" of a miss you would call this, but the dive definitely did not go as planned. I hope we learn some lessons from this one.

The plan was to do a deep dive, to 90 fsw. We calculated our turn pressure would be higher than rock bottom, and used the largest cylinders available, 100 and 95 cu. ft. We had gotten to about 80 ft nearby, so we figured it was about the same here. Well, it didn't get that deep; we maxed out at 69 fsw. So basically it was a long sideways swim over a mud flat. When we reached our turn pressure, we gave up on the planned 90 feet and turned back. We didn't make it all the way back at depth, and had to ascend in "blue" (actually green) water.

I don't know why, but on this dive the water just seemed "thick". I mean, you know how you glide a bit after you stop kicking? Didn't happen this time; as soon as I stopped kicking I'd stop dead. Weird. There wasn't any current to speak of; I mean it must have been moving something in the vicinity of 8 seconds to go 1 foot. Anyway, the point is, it seemed like a lot of work just to swim along, and we were using more air than usual. I was actually quite warm at depth; never really experienced that before. The water was about 52 F.

Well, before we made it back to the marina, my buddy signaled "750 psi", and "should we surface here or continue on, sharing your air?" Now, this was basically a night dive, so communicating something that complicated in the dark is, well, I didn't get the whole thing, but I did understand that she didn't have enough air to make it back to the marina at depth, so I gave her the thumb. So we did a "blue water ascent" with no visual reference. We've practiced this before, and actually didn't do terribly bad with the ascent and safety stop, but it was a bit up-and-down on the safety stop. She surfaced with 450 psi and I had 700. Then it was a long surface swim back.

1. I did not keep track of her air after the turn, so I was a bit surprised when she stopped and showed me 750 psi.

2. I did not pick up on the signals that she was getting anxious. It would have helped if I had signaled her to calm down earlier in the dive.

3. I let the fact that she was stressed cloud my judgement. Instead of calming her down, I let my stress level go up. Not terribly bad, though; in fact neither one of us was really all that stressed, and so I'm sure a lot of folks reading this may get the impression that the whole thing was worse than it actually was. It's just that we should have done better.

4. I should have shot the bag for our ascent, but, even though we have practiced this, I'm still not super-proficient at it and I didn't want to add another source of stress (see point 3).

5. We didn't discuss the contingency that the site may not be deep enough for our plan, so then what? One reason my buddy got stressed is that she was focused on reaching 90 ft, and when it looked like that wouldn't happen, she started swimming faster, using more air.

6. Even though we've worked on night signals, this dive made clear that we need to get better at signaling in the dark.

In the end, we didn't really come that close to disaster, it's just that we ought to know better. I've had dives where "if one more thing goes wrong I'll be in a world of hurt". On this dive I feel that, even though things were not going according to plan, we weren't really that far out of control and we probably could have handled one or two more unexpected snafus, but I'm glad I didn't have to find out.

 

[BlueKnight]

Thanks for sharing this sambolino. I have my first night dive comming up next week and will make sure that I discuss signals and communcation in the dark with whoever my buddy will be. Do you use your torch or hand signals? Having never done a dive at night it is hard to imagain how much you can see.

 

[TSandM]

Congratulations on doing a blue water ascent in the dark -- they're difficult.

I would definitely practice the bag shooting until you feel you can do it -- I don't know how deep you were when you decided to ascend, but most spools have at least 50 feet of line on them, so anything shallower than 40 or so, you should be able to remain in visual contact with the bottom and shoot the bag. If you are diving deeper than that, carrying a larger spool is a good idea. Having a bag and line REALLY helps with no-reference ascents.

I don't know how far out you were from the marina, but what I have done in a similar circumstance (the Gedney barges) when a buddy came to me surprisingly low on gas (but not critical) is share my gas with him while we closed the distance to a more desirable place to ascend. That way, when we got there, we could both go back to our own supply and ascend that way (and, if we got somehow separated or had issues with the gas sharing, we could always go back on our own gas and decide to ascend there).

The last thing I see here is the goal-fixation. My initial cave certification has as one of its limits, "no goal-oriented dives". Setting up a dive with a specific depth goal seems to me to be likely to cause some anxiety, especially if you don't know the site well enough to know if you can even GET that deep there. It is my personal feeling that depth alone should never be part of the goals of the dive, but simply part of the outside parameters (no deeper than "x"). Was there a specific reason why you guys decided to make 90 feet a goal?

 

[Bubbletrubble]

Do you use your torch or hand signals? Having never done a dive at night it is hard to imagain how much you can see.

@BlueKnight: Night dive communication utilizes a combination of torch (flashlight) and hand signals. But primarily communication is done with the light.

You will find yourself using a few important active light-only signals: circular "O" meaning "OK," rapidly moving light back and forth very insistently across your buddy's light beam meaning "attention," and moving the light along a direction of travel to signify "let's go this way."

For pretty much everything else, you have to first give the "attention" sign and then, when your buddy moves her light beam towards yours (meaning that you have her attention), you shine your light on your free hand and communicate the hand signal. Generally, after I give the hand signal, I'll flash the "OK" with my light. If my buddy understands, then she'll acknowledge with an "OK" sign of her own. I like to make my "OK" signals slow and deliberate to communicate that regardless of the issue, I'm calm and in control.

Passive light communication is very important. I can almost always tell if my buddy is doing OK just by seeing her light move methodically across the reef/rock wall/sand below. I'll try to position my light in her field of view to make it easier for her to track me -- she extends the same courtesy. It's even easier if she has a camera. As long as I see the flash firing away, I know that she's breathing and calm enough to be taking pics. If I know that she has a camera and she's not taking pics, then I wonder what's going on. She could be cold, have a leak in her drysuit, or dealing with a leaky mask.

During the initial descent, passive light communication can be very important. While descending at the same rate (which we always do), I can't look at my buddy's face, but I can look at her light. Generally, we'll shine our light on two nearby fixed points on the sand below so that we can monitor each other's status. Halfway down, I'll flash an "OK," which she'll return if all is going well. The initial descent can be fraught with ear equalization problems, mask problems, and other equipment issues. Be aware of this and allow for more frequent communication.

The one thing you should avoid doing is shining your light in your buddy's eyes (or anyone else's for that matter). If you do, you will blind them. It's not much fun having to work through any kind of problem under water while you can't see.

I'm sure others will chime in with a few other tips on night dive communication. I'm very anti-glow stick. Many think that it's a great way to mark the tank of your dive buddy. I think it's wasteful and bad for the environment. YMMV.

 

[Soakedlontra]

Congratulations on doing a blue water ascent in the dark -- they're difficult.

The last thing I see here is the goal-fixation. My initial cave certification has as one of its limits, "no goal-oriented dives". Setting up a dive with a specific depth goal seems to me to be likely to cause some anxiety, especially if you don't know the site well enough to know if you can even GET that deep there. It is my personal feeling that depth alone should never be part of the goals of the dive, but simply part of the outside parameters (no deeper than "x"). Was there a specific reason why you guys decided to make 90 feet a goal?

We began the ascent at about 50fsw. It was not totally dark I could still see the numbers on my computer display without having to use my light.Still , regardless of the amount of available light, it was quite an ordeal doing it under the amount of stress that we had to deal with. We would go up and down like two carts? on a roller coaster between 20 and about 11 fsw. We could not keep steady, neutrally buoyant at 15fsw at all except for a couple of seconds! It was quite exasperating.

However, ironically, despite the fact that our ascent was all over the place the fact that Sambolino44 agreed to ascend in the first place (I tried to signal to him to share air but he did not understand me so I figured that the only option I had was to suggest a blue water ascent) and the knowledge that I was going up toward the surface calmed me down. Those factors helped me to keep things under a certain amount of control preventing me to shoot to the surface like a SMB full of air!

You mention 'goal-fixation' well that was due to my stubbornness. Underwater stubborness can really put you into trouble as I noticed during this particular dive.

Right at the beginning I felt I had 'a mission' to accomplish: to dive at a max depth of 90fsw no matter what, I guess. This fixation really made me blind. When I realized that I would have never been able to reach that depth with the amount of air I had left at 69fsw and the kind of bottom we had to deal with I become anxious and worried about my air consuption, which was higher then usual due to the frantic swimming needed to reach those hypothetical 90fsw! And guess what? Air consumption got even higher!

Why was I so fixated with that particular depth? Because I have been feeling lately that I haven't done many dives deeper than about 70fsw and I wanted to practice diving deeper than that more.

As Sambolino44 mentioned, even before hitting the water our plan was a bit sketchy. For some mysterious reasons the possibility that our air supply may have been not enough to reach 90fsw did not surface in our minds. I guess we must have taken for granted the fact that during a previous dive at the same site but in a slightly different area we were able to reach 80 fsw without any problems.

 

[Bubbletrubble]

@Soakedlontra: Sometimes the goal isn't a depth...it could be a particular dive site.
A few years ago I had issues locating the "North Wall" at La Jolla Shores (local dive site). I did several dives that were, in my estimation, "unsuccessful." What generally happened was the following: my buddy and I would descend, take a heading, and then kick like a bat outta hell to find the under water structure. Frustrated with not finding the wall, we'd eventually do a blue water ascent and start the long kick back to shore.

In retrospect, I learned a great deal from those dives. I learned to set more realistic expectations. I developed better buddy communication skills. I practiced under water navigation. I became very comfortable with free ascents. In time, I bet the same thing will happen to you and your buddy.

It can be hard to communicate how much air you have left on a night dive. If you don't want to flash numbers on your fingers, just get your buddies attention, hold out your SPG in front of his face, and paint it with your light. He should be able to understand the situation and react accordingly.

After reading about what happened on the dive, I think you guys are being way too hard on yourselves. Relax. Lower your expectations for the dive, and you'll be pleasantly surprised when things work out.

 

[TSandM]

Two answers:

1. You've got the tools to figure out if you have enough gas to do what you want to do -- assuming you know enough about the site and the dive to fill in the blanks in the formulas. If you don't, the first dive should be reconnoitering, right? On a dive where you don't know what you are going to encounter, you set maximum parameters at the beginning, based on your rock bottom. In that case, getting below a certain amount of gas should have turned you, regardless of whether you had reached your goal.

I would also give some thought to the idea that this dive showed you that you really aren't ready, from a mental standpoint, to do deeper dives. Controlling anxiety and stress is key to coping with depth and narcosis. If there is anxiety to begin with, it's only going to get worse with reduced light and nitrogen's effects.

2. Holding stops in midwater at night is a challenge. A reference for vertical is a HUGE help. If you don't have one, using the particulates in the water to give you an idea of movement is very useful. This is one of the places where having the Liquivision computer is a godsend to me, because I don't have to backlight it or get my light on the face just so in order to read it. If you can put your computer on continuous backlight, it's very beneficial for ascents in the dark. Having a solid buddy is also a great help -- if both of you are unstable, it's REALLY hard to get the yo-yoing under control. I remember when Kirk and I were working on this, we had a night at Cove 3 where each of us had more than one uncontrolled ascent from the 20 foot range, simply due to disorientation and lack of reference. (That was the night I drove home and almost fell asleep at the wheel, and realized that decompression stress is real and that I was never going to do multiple ascents in one dive again.) I also watched my FAR more skilled buddy in Cozumel lose it, trying to run an ascent in dark, very clear water. It's hard.

I would highly recommend doing a lot of practice in direct ascents in the daytime (which I doubt you do, as you guys are like me, and do a lot of shore diving) before you challenge yourself with a direct ascent without reference at night. I'd also HIGHLY recommend a lot of practice shooting bags, because a bag is a lifeline for a free ascent in the dark.

 

[Bubbletrubble]

How many drysuit dives do you and your buddy have? If you're new to drysuit diving, you'll just have to be patient with the learning process. It takes time to work out trim/buoyancy issues. Perhaps that's what contributed to your inability to hold a shallow stop.

With some practice, doing a blue water ascent in a drysuit is not very difficult even without a visual reference -- the key is to trust your depth gauge/computer. I dive single tanks and here's what I do: At about 50 fsw, I shift any air from by BCD into my drysuit (exhaust from BCD and inflate drysuit enough to get neutral). Now I have both hands free. During the ascent, it's very easy to exhaust air from the dump valve (just tip my upper left arm up), which doesn't require the use of any hands. My left hand operates the light, and my right wrist has my computer strapped to it. With practice, I find that I can monitor my depth using the computer and keep an eye on my buddy. I guess shooting a line could help, but where I dive it's not common practice.

I agree with what TSandM recommended regarding practicing blue water ascents during the daytime first. When you get comfortable, then move onto performing the skill at night.

 

[sambolino44]

As far as using your light to illuminate hand signals, it's sometimes kind of hard to position yourself so that the light, your hand, and your buddy's eyes are all lined up right, depending on which side your buddy and your light are on. If you are facing each other, try to hold your light out toward your buddy and shine it back on yourself. Also, we're used to using some signs with two hands, so it's good to work out beforehand what the one-hand version will be. "Look" means you have to point your light at your own face, so close your eyes. "What's your air?" turns into just shining your light on your own gauge. "Level off" is just a flat, palm-down hand going sideways. "Buddy up" can be just two fingers on one hand, but try to make that look different from "seven" by holding your hand palm down. We've usually been able to see the shrug for "What?" or "Question" just by kind of holding your light on yourself when you do it.

 

[BlueKnight]

Thanks for all that information Bubble. I apologise for the thread hijack but seemed a good lesson to take away as well as valuble information for a newb. I know there are some tecniques for preserving night vision (closing one eye for example) as well as not looking directly at what you wish to see (at night the center of the eye cannot pick up as much light as around the edges) but I can imagain that one can get disorentated pretty quick. Still a bit nervous about the night dive but I will try anything once (twice if I like it )

Good job on the OP for holding it together.