Strobe dropping?

[cerich]

I've never seen a commercial diving operation "lay lines" in the sense that recreational divers do. We just follow our umbilical out.The line failures we see are related to heavy lifts at sea, and rigging tools and loads on the worksite, and securing loads on deck. Failures are less common in offshore oilfield maintenance than on salvage operations because support requirements are more predictable, but they still happen often enough to build-in safety factors that are unheard of onshore.

That experience leads me to use line on Scuba that is much closer to what a mountain climber uses than to fly a kite.

we are talking vastly different uses of lines, and in the context I am using a line is not pulled on, doesn't support a load etc

 

[Akimbo]

we are talking vastly different uses of lines, and in the context I am using a line is not pulled on, doesn't support a load etc

Understood, but that doesn't move my comfort zone. Just because you don't intentionally pull on a line doesn't mean that you won't accidentally back into it after something shifts and you're in the dark. I hate handling small stuff underwater anyway, even with a reel. Besides, how are you going to get that binnacle on deck with a piece of string?

 

[CAPTAIN SINBAD]

So what I am understanding from this conversation is that commercial divers had other means to their disposal such as blowing or cutting their way into the wreck. This meant that line work (which is imported from cave diving practices) was not really as useful for their purpose. When recreational wreck penetrations began, recreational divers did not have the cutting tools or explosives at their disposal.They were forced to replicate cave diving techniques into the wreck. This may not make sense to hard core commercial divers but my question to commercial divers is if you guys did not have explosives or other hole making things at your disposal, then would you still regard the use of lines as unreliable? If yes, what option would prefer.

To those who have taken Chattertons wreck course, he talks about using multiple methods on a single dive. These would be:

Wreck line
Strobes
Progressive Penetration

What else?

Thanks for everyone's input. This has been one of the most enlightening threads to me.

 

[USMC CPL.]

@oldschoolto

Is that it or is the difference more sightseeing versus salvage?

I do notice a lot of naivety of divers that have never lived aboard ship. Every new sailor has been lost onboard navy ships even though every passageway, door, and ladder is clearly labeled. It doesn't take much imagination to understand that it is waaay harder after the paint is gone, she's on her side, and the lights of off.

I was on a Naval ship and nothing was posted.

 

[Akimbo]

... my question to commercial divers is if you guys did not have explosives or other hole making things at your disposal, then would you still regard the use of lines as unreliable?...

It depends on how you define "line". Line in the maritime industry is defined as anything from twine to hawsers. It all comes down to what you are willing to bet your life on.

Diving, and life for that matter, is all about risk management. I have not been in a situation where I couldn't get to any point on a wreck that was more than 200' (100' straight line) from an existing access point. I may have had to clear debris or break something but I didn't need a cutting torch or explosives. I can easily carry 200' of 1/2" double-braided Nylon line.

So, how confident are you that you can get back to sunshine with the gas on your back at the end of your planned dive after vis drops to zero? I always work on this premise:

Wreck divers will eventually find themselves in black-out conditions. It really doesn't matter why. All your lights can fail. Silt can be stirred up by an awkward move, another diver, shifting debris, or wresting a prize binnacle to sunlight. In the end you are in the dark and have to deal with it.

How much longer will it take you to untangle yourself if you get fouled on your cave-line than 1/2" line? What are the chances that cave line will part under these conditions compared to 1/2" line?

The next question is: why do I want to go there? This story always comes to mind:
Wreck Penetration

It isn't often that I get to be one of the most conservative voices on Scubaboard.

 

[Akimbo]

I was on a Naval ship and nothing was posted.

It depends on what you mean by posted. Forward torpedo room or galley... not so much. I mean like 4-95-3-L for 3 decks below the main deck, 95th frame from the bow, 2nd compartment on the starboard side from the centerline, Living space. OK, I'm not that good. I looked it up in my Blue Jacket's Manual.

 

[USMC CPL.]

It depends on what you mean by posted. Forward torpedo room or galley... not so much. I mean like 4-95-3-L for 3 decks below the main deck, 95th frame from the bow, 2nd compartment in the starboard side from the centerline, Living space. OK, I'm not that good. I looked it up in my Blue Jacket's Manual.

I was being a smart $#@. I was on the USS Belleau Wood in 94 and all they gave us was a crappy paper map. Most of the time we found where we were going by mistake. Of course Navy really didn't like us being on their ship.

 

[Akimbo]

I was on the USS Belleau Wood in 94 and all they gave us was a crappy paper map.

Oh that's because you got the leatherneck map. All us squids ran a pool on how long it would take you to pee over the side because none of the heads were on your map.

 

[cerich]

I was on a Naval ship and nothing was posted.

not a chance, you missed them. every bulkhead with a pass thru and many/most without has a number placard

 

[cerich]

Understood, but that doesn't move my comfort zone. Just because you don't intentionally pull on a line doesn't mean that you won't accidentally back into it after something shifts and you're in the dark. I hate handling small stuff underwater anyway, even with a reel. Besides, how are you going to get that binnacle on deck with a piece of string?

it isn't dental floss, it is actually fairly strong..