26 replies to this topic

[GentDiver]

All,

So last night was the book work for my AOW and the instructor asked the following question.

"If you loose your buddy and your lights, what do you do?" Well the answer is calmly ascend to the surface and look for your buddy there. The instructor then asked, "Well how do you know which direction is up? You can't see your bubbles as it is to dark." So I suggested that you put some air in your BC to determine which direction is up and then start your safe ascent. Well they thought I was a crazy man, which ok I may be, but this seemed like a reasonable way to determine the way up.

Did I miss something? What would you guys do?

Scott

:lam:

[Walter]

How experienced is your instructor? How many night dives has he logged? Has he ever swam around without a light?

I routinely dive without turning on my light at night. Unless the night is especially dark or the water especially murky, you will be able to see your bubbles as well as the moonlight on the surface. Even if you can't see anything at all, you'll be able to feel your bubbles. You can determine their direction of travel (up) by feeling them move past you. Also, unless you lost your light in a vortex that was spinning you, you'll already know which way is up. Your suggestion is not a bad one if you just add a tiny amount of air, taking a deeper breath might be a better, although similar, plan. Both options will cause you to rise. You should also still be able to see you buddy's light unless he lost his as well.

[peterbj7]

The short answer is that you should never lose all your lights, because at least one should be fixed to your BCD/harness. Plus I've never been on a night dive without significant ambient light, even with no moon and no other divers. If you're in a cave or a wreck without a light your planning was somewhat deficient. But to answer the substantive question, I think I know which way is up even with my eyes closed. I wouldn't inflate my BCD, but just my lungs. If I was neutrally buoyant to start then I'll start going up. If I wasn't then either I was in some way supported or I was descending.

A tougher question is "with no mask and in darkness how do you know when you've stopped ascending?". To do a safety stop, for example.

[Cold_H2O]

The short answer is that you should never lose all your lights, because at least one should be fixed to your BCD/harness.

Having logged most of my dives in the murky waters of Puget Sound..(Think 10-20 vis = a good day).
The #1 rule here is ALWAYS HAVE A BACK UP!!! (2 lights,2 knives.....spare air)
This means you enter the water equipment heavy...but if things get ugly you are usually prepared..
I have never lost up.. I have been told it can happen. I would also agree with Walter, a good breath will help direct you up.

[Diverbrian]

All,

So last night was the book work for my AOW and the instructor asked the following question.

"If you loose your buddy and your lights, what do you do?"  Well the answer is calmly ascend to the surface and look for your buddy there.  The instructor then asked, "Well how do you know which direction is up?  You can't see your bubbles as it is to dark."  So I suggested that you put some air in your BC to determine which direction is up and then start your safe ascent.  Well they thought I was a crazy man, which ok I may be, but this seemed like a reasonable way to determine the way up.

Did I miss something?  What would you guys do?

Scott

:lam:

Walter is absolutely correct. Being of "danglie hating" persuasion, I also don't use tank lights (which many recreational agencies want you to have). If you can't see my 10 W HID or either of the back-up lights that I would be using (in the event of a light failure), either it's too murky down there to be night diving or you have vision problems.

I personally feel that daylight diving in murky water is more challenging than night diving. It is often more difficult to see another diver by their light beam in those conditions.

I go with the "inhale and you will start heading up" theory myself. But, as Walter says, you will likely feel the bubbles on your face from your exhalation.

Edited by Diverbrian, 16 February 2005 - 11:03 PM.

[GentDiver]

Ok that all makes sense. yeah I wasn't talking about putting much air in the BC just a little to change your bouyancy. The deep breath is a great idea I never thought of that.

Remember we are talking about Monterey here so vis is 30-40 feet.

Thanks!

Scott

:lam:

[Brinybay]

All,

So last night was the book work for my AOW and the instructor asked the following question.

"If you loose your buddy and your lights, what do you do?" Well the answer is calmly ascend to the surface and look for your buddy there. The instructor then asked, "Well how do you know which direction is up? You can't see your bubbles as it is to dark." So I suggested that you put some air in your BC to determine which direction is up and then start your safe ascent. Well they thought I was a crazy man, which ok I may be, but this seemed like a reasonable way to determine the way up.

Did I miss something? What would you guys do?

Scott

:lam:

He was either being hypothetical or he doesn't know what he's talking about. Just because it's dark doesn't mean you lose all sense of direction, and he's wrong, you can still see your bubbles, and I don't refer to them to get my bearings. That's only if you get vertigo.

The answer is you look for your buddy's light. "Go to the light!" If I lose my buddy and can't see their light, I start waving mine around in all directions so they can spot it. Around here, they could be just 10ft away. When that fails, I turn mine off and let my eyes get accustomed to the dark (I usually do that anyway for a few minutes, it's eeire!) More often than not, there is usually some ambient light from street lights or buildings or the moon that will help you spot their bubbles. I carry a redundant light even during the day. I've never had vertigo in over 500 dives and only once did I hear about anybody else getting it while diving. I only ascend as a last resort, and even then I've rarely found my buddy that way.

[jextract]

Agree with all other posts here. Always have a backup light. Don't forget that your computer also has a light that, while you can't use it for direction at a minimum you can put it next to your dump valve to track the bubbles. I've done plenty of night dives and have always been able to see with the ambient light. In fact, one of the best dives I've ever done in my life was with Kamala at the Salt Pier in Bonaire at night. The moonlight was so bright I did the vast majority of the dive with no artificial light at all!

And I agree with Brian, it is much more disorienting to dive with zero visibility during the daytime when the light seems to have no direct source.

[scubafanatic]

Hi Scott,

........I always do my night dives with a primary 10W HID cannister light and a pair of back-up lights..........the odds are against a triple light failure.

....for the sake of argument, even absent lights, my back-lit AI computer shows my depth, you can use that display to show you whether you're ascending/decending, sort of like an aircraft pilot navigating on instruments.

...another option is to let your SPG or hosed-computer dangle loose, gravity will pull it 'down', you can use your hand to feel along it's length and determine where 'down' is.

.....I'm leary of adding air to the BC to determine up.......it's way too easy to initiate an out of control ascent and imitate a Polaris missile.......

.....another low-tech direction finding technique is pay attention to your ears......if they start to hurt you know you are decending in the water column, since you will feel the need to equalize them......if you ascend, you will feel/hear them 'popping' as the extra air escapes.

Karl

[Cold_H2O]

.....another low-tech direction finding technique is pay attention to your ears......if they start to hurt you know you are decending in the water column, since you will feel the need to equalize them......if you ascend, you will feel/hear them 'popping' as the extra air escapes.

Karl

I never thought of that method.. But after little thought.. It truely is a can't miss method..
Thanks Karl one more thing to share with new divers

[TheSassyRabbit]

I agree with the previous posts so I won't add too many additional comments. I've had more situations where I've had to track my bubbles by feeling them in murky water than at night (especially in the mud holes we have for local diving in TX!).

Just out of curiosity, what did the instructor offer as an answer?

[H20 Bug]

Ok that all makes sense.  yeah I wasn't talking about putting much air in the BC just a little to change your bouyancy.  The deep breath is a great idea I never thought of that.

Remember we are talking about Monterey here so vis is 30-40 feet.

Thanks! 

Scott

:lam:

Scott -

That should be 30 to 40 INCHES of vis in Monterey - cause it's more like 3 to 5 FEET on an average day, especially at Breakwater. We had 10 feet of vis at Breakwater one morning and were just delighted.

I usually have 3 lights in Monterey - my primary, my backup, which is not much smaller than my primary, and my favorite little warm water light tucked into my BC pocket, just in case - I really don't like the dark, in the water or on land.

[GentDiver]

That should be 30 to 40 INCHES of vis in Monterey - cause it's more like 3 to 5 FEET on an average day, especially at Breakwater. We had 10 feet of vis at Breakwater one morning and were just delighted.

I usually have 3 lights in Monterey - my primary, my backup, which is not much smaller than my primary, and my favorite little warm water light tucked into my BC pocket, just in case - I really don't like the dark, in the water or on land.

Thanks for the info. BTW, we are doing our night dive on Saturday and our Nav dive on Sunday. I'm excited but a little nervous. Nervous mostly becuase of all the stories I have heard about the vis. I'll post a dive/class review on Monday.

Scott

:lam:

[Cold_H2O]

Thanks for the info. BTW, we are doing our night dive on Saturday and our Nav dive on Sunday. I'm excited but a little nervous. Nervous mostly becuase of all the stories I have heard about the vis. I'll post a dive/class review on Monday.

Scott

:lam:

Don't be nervous.. Night dives are great.. I enjoy diving a site during the day and then diving it again at night.. Same site different world!!!
About the stories...Something about the ocean brings out the story teller in all of us..Can't wait to hear yours

[Funewgy]

In fact, one of the best dives I've ever done in my life was with Kamala at the Salt Pier in Bonaire at night. The moonlight was so bright I did the vast majority of the dive with no artificial light at all!

Yeah, yeah. It was one of your best dives because you were with Kamala. It didn't have anything to do with the damn light. Just admit it.