Hanging off a lift bag line

[wrybosome]

Hi all, I have a question for you. A reference to Diver0001's task management post got me thinking about this.

The scenario is that you've become disoriented on the debris field of a wreck dive and no longer know where the up line is. Rather than continue to search for it you shoot a bag to the surface and tie off to a piece of debris, using the line to ascend.

In conditions of say 1 kt current and 3 - 4' seas, is there much danger of the line breaking just from tension while your hanging off it? Say while bouncing up and down on your safety stop?

I ask because on the reel/line/bag combination I was advised to get at the LDS the line seems pretty thin and the thought has kind of been bugging me.

Thanks, Tim.

 

[Dr Wu]

Hi all, I have a question for you. A reference to Diver0001's task management post got me thinking about this.

The scenario is that you've become disoriented on the debris field of a wreck dive and no longer know where the up line is. Rather than continue to search for it you shoot a bag to the surface and tie off to a piece of debris, using the line to ascend.

In conditions of say 1 kt current and 3 - 4' seas, is there much danger of the line breaking just from tension while your hanging off it? Say while bouncing up and down on your safety stop?

I ask because on the reel/line/bag combination I was advised to get at the LDS the line seems pretty thin and the thought has kind of been bugging me.

Thanks, Tim.

Impossible to say as the degree of tension the line is under is different in every situation.

If this concerns you there is a solution:

 

[TSandM]

I believe people who use what I think is called a Jersey upline tend to use heavier line than the cave line which is standard on spools and reels. There is a very real risk of metal cutting through cave line if the surface is choppy, or the diver is overly reliant on the line for buoyancy control or managing current.

 

[Cave Diver]

I believe people who use what I think is called a Jersey upline tend to use heavier line than the cave line which is standard on spools and reels. There is a very real risk of metal cutting through cave line if the surface is choppy, or the diver is overly reliant on the line for buoyancy control or managing current.

This is a jersey upline picture below. Most commonly used among NE wreck divers.

Impossible to say as the degree of tension the line is under is different in every situation.

If this concerns you there is a solution:

 

[Cave Diver]

Hi all, I have a question for you. A reference to Diver0001's task management post got me thinking about this.

The scenario is that you've become disoriented on the debris field of a wreck dive and no longer know where the up line is. Rather than continue to search for it you shoot a bag to the surface and tie off to a piece of debris, using the line to ascend.

In conditions of say 1 kt current and 3 - 4' seas, is there much danger of the line breaking just from tension while your hanging off it? Say while bouncing up and down on your safety stop?

I ask because on the reel/line/bag combination I was advised to get at the LDS the line seems pretty thin and the thought has kind of been bugging me.

Thanks, Tim.

Yes, I would say there is a danger of it breaking. Another solution would be to shoot the bag and tie it off and just use the line as a visual reference for the ascent rather than holding on to it.

This may be difficult in heavy current, in which case it may be better to shoot the bag so the boat can see you and just drift with it. If you're not comfortable with the boats ability to notice, track and recover you, I'd pick a different boat.

 

[mike_s]

I've seen Jersey lines before. typically the pics or descriptions were twine type line, as seen in the above pic. (wether it's 1/8" 1/4" ,etc.


I was thinking wouldn't parachute type cord line be stronger and thinner perhaps?

 

[MXGratefulDiver]

Well first off ... if you're hanging onto a fixed line that's attached to a bag and the current's that strong, you're gonna pull the bag down long before there's enough tension on the line to break it.

Secondly, cave line's got an awful lot of strength for its size ... if you want to find out, tie a piece around a tree or some other immovable object and try using just your body strength to break it.

The one time I found myself in the scenario described in the OP, I didn't tie into the wreck ... I shot the bag and did a drifting deco. The purpose of the bag isn't to give you a line to hang onto ... it's to let the boat know where you are.

... Bob (Grateful Diver)

 

[Dr Wu]

I've seen Jersey lines before. typically the pics or descriptions were twine type line, as seen in the above pic. (wether it's 1/8" 1/4" ,etc.


I was thinking wouldn't parachute type cord line be stronger and thinner perhaps?

Yes it would but the jute used in a Jersey line disolves quickly making it a bit more enviromentally friendly.

 

[Laurie S.]

Thank you, now I get it! I just did the classroom portion of my SSI wreck diving class last night and the one thing I didn't fully understand is why use an upline. I haven't used one to date yet (yeah, huge total of 18 dives, LOL) and have no problem maintaining a safety stop. My instructor said the upline was make sure you're going up slowly enough, but I do that by watching my computer. It makes much more sense to me now that the real purpose is to let the boat know where you are.

 

[TechBlue]

In the NE they frown on shooting a bag and drifting, not many people use the old Sissal reels anymore because as Dr Wu said it is enviromentallf friendly and does decay overtime. In the NE most divers now keep a 3' or so length stashed, if they need to tie off to the wreck they use that then attach their wreck reel which use a heavier line than cave line. Once you are on the boat you tie off and snap the sissal this avoids having line drifting all over the wreck leaving an entanglement hazard.