Zero vis lost line search

[WhiteSands]

I'm cave trained and was wondering what the protocol is for wreck divers.

For caves, we are taught a few searches but the go to is the shotgun aka bicycle spoke search pattern. It involves doing a primary tie off with the safety spool then a secondary tie off as a direction reference then going in a spoke pattern to search for the line.

However to do this you need something to tie off too. In wrecks, where the deck is flat, I don't see this being feasible.

What do wreck divers do to search for a lost line?

 

[northernone]

I'm cave trained and was wondering what the protocol is for wreck divers.

For caves, we are taught a few searches but the go to is the shotgun aka bicycle spoke search pattern. It involves doing a primary tie off with the safety spool then a secondary tie off as a direction reference then going in a spoke pattern to search for the line.

However to do this you need something to tie off too. In wrecks, where the deck is flat, I don't see this being feasible.

What do wreck divers do to search for a lost line?

Pray to any known deity and invent a few.

Fast answer, it's quite common for a wreck to have plenty of tie off points. And that's how I was trained.

Longer answer will come from a much more experienced diver:

Relocating a Lost Guideline | Skills for Wreck Divers

 

[Aotus]

i'm trying to imagine a space in a ship with all smooth surfaces, nothing on the floor, that is so immense that going to wrong direction will lead you off into bad news, with zero vis. A cargo bay?

I'm not experienced in wrecks, at all, but is this a thing?

 

[Kevrumbo]

On the Truk Wrecks: Any large enclosed overhead area, such as a crew hammock berthing space, or a cargo bay -can be hard to quickly locate a primary tie-off. Seventy years of silt layers 2 feet thick or more, or lots of loose debris or objects such as hundreds & hundreds of toppled sake/beer/wine glass bottles makes it difficult to find & make a secure tie. To complicate matters, on a capsized wreck, what used to be floors are now walls or ceilings & vice versa; you might be in a section where all you have is a long straight run of smooth superstructure without portholes, light stanchions, piping etc -->that is no fixture easily found to tie onto.

A tricky to bad situation to lose sight of the Primary guideline is around a corner corridor or going up through a vertical gangway; or going thru 'Black Hole' caverns -large burned out blackened ship spaces that totally suck-out the illumination from your canister light (and where the worst of all zero-viz conditions can occur -"Black Ash Silt-outs"). Add some contanimated water around you (leaking bunker/fuel oil or caustic cargo aviation fuel) and you've got the lostline Wreck Diver's Nightmare. . .

 

[northernone]

On the Truk Wrecks:

Snip

you've got the lostline Wreck Diver's Nightmare. . .

Way beyond my experience, what's the contingency plan for those conditions? How have divers ended up back on the surface?

Much to learn.

Regards,
Cameron

 

[bl6394]

Way beyond my experience, what's the contingency plan for those conditions? How have divers ended up back on the surface?

Much to learn.

Regards,
Cameron

If you've got the gas (or on a rebreather) - be still. The vis may improve to the point of finding your way back out. Also - use multiple means of navigation (not just relying on the pen line): progressive penetration, placing strobes at key junctions, exact depth and direction (magnetic compass), and lines of the wreck.

Caves frequently imply a greater distance to open water. Wrecks - while frequently less stable than a cave - have a shorter distance to open water. The line doesn't have to be (shouldn't be) your only means of navigation.

 

[Kevrumbo]

Way beyond my experience, what's the contingency plan for those conditions? How have divers ended up back on the surface?

Much to learn.

Regards,
Cameron

Lost Buddy Protocol -your lead teammate coming back to find you and you're lucky enough to just see his primary light. Especially with an experienced leading wreck guide, the contingency plan agreed beforehand is to wait 30sec before initiating a lost line or wreck egress opening search, and during that time alternately covering your light and looking for the wreck guide's primary light (ideally you may have just momentarily lost sight of your lead wreck guide as he turned a corner in a deteriorating, "raining percolation & particulate" low viz condition -which was my saving grace). Can be difficult to find each other in a corridor with zero-viz silt-out conditions. But could be impossible to find each other in time -on Open Circuit- over a large overhead open area like a cargo bay or hangar deck.

 

[lermontov]

my first thought is why are you in a no light penetration without a line.

But- Situational awareness is the key. If Im in a wreck in a no light area even I'm constantly referencing my location to other tactile objects (doorways gas bottles stools table etc.)and then reference that back to another point etc the more information you can absorb the better off you are, you can build up a mental picture of the room as you go . Like Kev. said put your torch against your body to see if yo can see any light (torch or natural) and wait for the silt to settle a little. rule number 1 don't panic - stop and think
If you visit the wreck regularly then all the better - i have an escape plan for most areas I go and I discuss with my buddy predive. Every wreck is different of course but my protocol is progressive penetration with line depending on complexity. If theres existing lines then I stay with in 2m of such and am constantly monitoring where I am in relation to it

hope that helps

 

[Kevrumbo]

my first thought is why are you in a no light penetration without a line . . .

Well . . .such is the Truk Lagoon Wrecks planning dilemma:

Especially for the GUE Cave and UTD Wreck-trained Divers as to overhead protocol: you will either be with a dive guide who will lead your team on traverses through the shipwrecks' cargo holds, superstructures & engine rooms etc. --all without running line-- or choose to run a reel-line & egress out on reel-line without using a leading dive guide.

The advantage of running a reel-line is of course safety & standard operating overhead procedure as trained; the disadvantage is that you won't have as much bottom time to fully & efficiently explore the wreck than if you did a through-and-through traverse. In other words, the dilemma will be whether to do "Trust-Me" dives with a Dive Guide or not. . .

The Trust-Me Dive goes both ways in Truk --the Guide is vetting you on the initial easy shallower checkout dives, making sure of your general trim & kicking technique as well as your aptitude & temperament for wreck diving. He's gotta be sure that you won't panic when the rust & silt starts "percolating" all around you, far inside an engine room at 51meters depth. . .

There will be times where you will be in a tight engine or crew space in a near silt-out or "Black Hole Cavern" as described above; or momentarily lose sight of the Guide around a corner corridor or up through a vertical gangway (especially a disorienting vertical passageway in a capsized ship that was once a lateral corridor of 12 meters length or more -IOW, you might have to counterintuitivly descend 12 meters or more to egress the hull/superstructure); You have to trust that the Guide knows where you are at all times as well as all wreck egress pathways, and the Guide has to know that you won't make a potential lost diver contingency worse by freaking out. . .

A compromise best solution is to have a "Pathfinder Team" --that is a team laying line with a Dive Guide in front leading a traverse through the wreck; and then having other teams come in later following that line to video/take pictures/sight see artifacts etc. --and then finally later a "Clean-Up Team" to reel-in the guideline, while traversing back in the opposite direction and winding-up reel-line. . .

 

[lermontov]

Well . . .such is the Truk Lagoon Wrecks planning dilemma:

Especially for the GUE Cave and UTD Wreck-trained Divers as to overhead protocol: you will either be with a dive guide who will lead your team on traverses through the shipwrecks' cargo holds, superstructures & engine rooms etc. --all without running line-- or choose to run a reel-line & egress out on reel-line without using a leading dive guide.

The advantage of running a reel-line is of course safety & standard operating overhead procedure as trained; the disadvantage is that you won't have as much bottom time to fully & efficiently explore the wreck than if you did a through-and-through traverse. In other words, the dilemma will be whether to do "Trust-Me" dives with a Dive Guide or not. . .

The Trust-Me Dive goes both ways in Truk --the Guide is vetting you on the initial easy shallower checkout dives, making sure of your general trim & kicking technique as well as your aptitude & temperament for wreck diving. He's gotta be sure that you won't panic when the rust & silt starts "percolating" all around you, far inside an engine room at 51meters depth. . .

There will be times where you will be in a tight engine or crew space in a near silt-out or "Black Hole Cavern" as described above; or momentarily lose sight of the Guide around a corner corridor or up through a vertical gangway (especially a disorienting vertical passageway in a capsized ship that was once a lateral corridor of 12 meters length or more -IOW, you might have to counterintuitivly descend 12 meters or more to egress the hull/superstructure); You have to trust that the Guide knows where you are at all times as well as all wreck egress pathways, and the Guide has to know that you won't make a potential lost diver contingency worse by freaking out. . .

A compromise best solution is to have a "Pathfinder Team" --that is a team laying line with a Dive Guide in front leading a traverse through the wreck; and then having other teams come in later following that line to video/take pictures/sight see artifacts etc. --and then finally later a "Clean-Up Team" to reel-in the guideline, while traversing back in the opposite direction and winding-up reel-line. . .

yes i understand -its not what I would prefer but its the reality for some areas in the way the commercial operators function. Ive been in similar situation of trust me dives with experienced tech divers -BUT I've had the opportunity to assess them too and there are some DM I wouldn't trust.
Its personal risk thresholds that self monitor and I simply dont like not having control of that.