Zero vis lost line search

[Aotus]

Am I reading this correctly? You don't run a line because it's not as fun!? Is wreck diving THAT different than cave diving? There are traverses in caves too. You can either lay a permanent line ahead of time, go back for your temporary line, or stop whining that you can't go as far on one dive and and make it two from opposite directions.

I must have misunderstood. Right?

 

[bl6394]

Am I reading this correctly? You don't run a line because it's not as fun!? Is wreck diving THAT different than cave diving? There are traverses in caves too. You can either lay a permanent line ahead of time, go back for your temporary line, or stop whining that you can't go as far on one dive and and make it two from opposite directions.

I must have misunderstood. Right?

Wreck diving is very different than cave diving.

(Distance) I may have several thousand feet of penetration at Jackson Blue - but would rarely lay several thousand feet of line in a wreck. (Line Abrasion) Older wrecks are filled with many razorlike edges - having a cut line is a distinct possibility. I've never had a cut line in a cave - although they do abrade over time. (Unstable) wrecks are much less stable than the kind of caves that I usually dive. There is a greater possibility of entanglement or entrapment.

I usually run a line in a wreck, but I supplement that navigational technique with others I previously mentioned. Sometimes (in a submarine for instance) the value of running a line is offset by the risk of entanglement - and I'll use progressive penetration.

Bottom line - it really depends upon the type of wreck.

 

[Aotus]

A cave may be thousands of feet long, but the lines we lay each dive are usually only a 20-50' to the mainline, or to a jump. In an overhead, with risk of zero vis and/or need for speedy egress, I don't think distance can be the justification for not laying a line.

 

[lermontov]

A cave may be thousands of feet long, but the lines we lay each dive are usually only a 20-50' to the mainline, or to a jump. In an overhead, with risk of zero vis and/or need for speedy egress, I don't think distance can be the justification for not laying a line.

no its not but each wreck dive is somewhat situational. As above says if you've got long narrow corridor leading to an open door to open water then no point in placing a line. however if that same corridor was wider with multiple rooms off it and a dog leg then yes a line would be prudent. if your 5-10 m from an escape window then its less of a threat that doing a deep mutideck penetration in a big ship. in short the more complex the wreck the more inclined to put a line but if your wreck is spatially easy to navigate then i dont run a line as long as you recognise where the tippping point is. which gets back to what Kevrumbo mentioned about diving at trukk and what you're experience /comfort level is

 

[Kevrumbo]

In Truk on the popular shallower wrecks 18 to 33m depth range, a stem-to-stern full ship length traverse lead by an experienced wreck guide through cavern type cargo holds and superstructure overhead passageways can be considered as one long progressive penetration. There are usually exit/egress openings visible along the route.

Truk Lagoon - Lust4Rust Wreck Diving Trips

The only time we would run a line is going into a multi-level black hole labyrinth of an engine room especially 45m or deeper where there is only one entryway/exit way. To lose the penetration line low-viz in this environment can be just as bad or worse than a zero-viz lostline scenario in a large open space area: you would be constantly running & banging into machinery with potential safety spool entanglement points (boiler pipes & tubes, catwalks, railings, stairs, ladder rungs, engine fixtures, levers, valve control wheels, tool spanners etc), while searching for the mainline. Again, the way we dealt with this contingency was to momentarily hold in place in Lost Buddy Protocol for at least 30sec, before initiating a safety spool lostline search as a last resort, given all the hazards listed above. . .

On my last 2015 Truk trip, lost my lead Guide off the reel mainline tie-in, inside the engine room "tomb" of the Aikoku Maru at nearly 60m deep in hazy visibility conditions (he literally "disappeared" in front of me into a bulkhead wall as he did a zig-zag around a partition which had the illusion of looking like he dematerialized through a solid continuous wall). Was probably no more than 20 seconds before my buddy found me but it seemed like an eternity. I stayed put where I was and started laughing through my Reg in amazement of what I thought I saw: Buddy said he heard the laughter and it helped to locate my whereabouts and was reassured that I wasn't in panic -albeit my laughter was starting to become somewhat louder & hysterical as he finally found me (and actually I was just about to deploy my safety spool for a lost line search).

 

[WhiteSands]

Seeing that one of the top factors of overhead trained divers dying in an overhead environment is not laying a guideline all the way to OW, I don't see that as an option for me at all. Unless its some kind of direct swim through in a very small wreck.

I also have not experienced any difficulty in speaking to a responsible wreck guide and agreeing to lay line in. If we want to go deeper in, the guide will lay the line. Otherwise for practice either myself or one of my buddies would take turns doing it. If we're planning to hit an engine room deep inside we just take 2 dives to do it. The first dive we run line in then leave the reel there. That makes the second penetration much quicker.

No line means no options since almost all emergency contingencies depend on the line being there!

From the replies I guess I can conclude that wreck divers have a similar protocol as far as a lost line search is concerned?

 

[WhiteSands]

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?

Typically in the passageways you would find something to tie off to. Problems I've encountered in finding tie off points was when travelling through cargo holds, rope storage rooms etc.

One of the important rules when lost (at least in caves) is to find a tie off immediately before you start to drift away from your initial location and start to lose all sense of direction. So its important to find a tie off point quickly and close by.

I thought that might be a problem in some parts of a ship and wonder how wreck trained divers deal with that.

 

[Kevrumbo]

. . .

One of the important rules when lost (at least in caves) is to find a tie off immediately before you start to drift away from your initial location and start to lose all sense of direction. So its important to find a tie off point quickly and close by.

I thought that might be a problem in some parts of a ship and wonder how wreck trained divers deal with that.

Other than a huge open semi-overhead space like an Aircraft Carrier Hangar Deck, generally we don't have to worry about "flow" currents deep inside a wreck causing a zero viz lostline diver to drift away as you would in a cave -hence it's not as critical a tactic to immediately find a safety spool tie-in point. Usually just staying put and not wandering further away is the preferred contingency tactic if you momentarily lose your Lead teammate, and wait 'til he comes back to locate you.

 

[rjack321]

Typically in the passageways you would find something to tie off to. Problems I've encountered in finding tie off points was when travelling through cargo holds, rope storage rooms etc.

One of the important rules when lost (at least in caves) is to find a tie off immediately before you start to drift away from your initial location and start to lose all sense of direction. So its important to find a tie off point quickly and close by.

I thought that might be a problem in some parts of a ship and wonder how wreck trained divers deal with that.

A couple of things come to mind here.

Most wreck dives I've done I've either got the reel in my hand or a buddy has it in his/hers. So at least one of you is going to have to actually drop the reel to lose the line. I don't think I have ever done a wreck dive relying on a pre-installed line like in most tourist caves. So are you dropping the reel or are you the #2 or #3 diver behind the leader laying the line? Or using a pre-installed line? I hesitate to call any line permanent in a wreck.

 

[Kevrumbo]

A couple of things come to mind here.

Most wreck dives I've done I've either got the reel in my hand or a buddy has it in his/hers. So at least one of you is going to have to actually drop the reel to lose the line. I don't think I have ever done a wreck dive relying on a pre-installed line like in most tourist caves. So are you dropping the reel or are you the #2 or #3 diver behind the leader laying the line? Or using a pre-installed line? I hesitate to call any line permanent in a wreck.

Primary Reel tie-off inside a large cargo space or engine room while you go look around the compartment without running a secondary spool guideline (essentially performing a potential treacherous "visual jump"), you can lose the primary line as well in an inadvertent developing low viz situation like -for example- raining silt particulate caused by open circuit exhaust bubbles.