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Relocating a Lost Guideline – Skills for Wreck Divers

Technical Diving knowledge share by Andy Davis

This article, by Jim Wyatt, was originally published in Underwater Spelology.  I have reproduced the article here, as the issue of relocating a lost guideline also demands the attention of wreck divers at all levels.

Wreck Diving Danger In the event of a silt-out, or light failure, inside a wreck, it can be remarkably easy to loose orientation to the guideline – even if you are very close to it. When vision is lost, the diver can drift, rotate or rise/sink very rapidly in relation to the guideline. Disorientation from the guideline the requires a search – which is a surprisingly difficult proposition underwater and in zero visibility.  Spontaneous searches, without the use of a safety spool for reference/security, has led to many diving fatalities inside shipwrecks.  The diver is disorientated and can easily progress further from the line, losing themselves within the confusing lay-out of a wreck.

Jim’s advice for cave divers is equally appropriate to those interested in safely exploring the inside of wrecks…

Relocating a Lost Guideline

by Jim Wyatt

One of the many skills cave instructors teach at all levels of cave diver training is the procedure for relocating a lost guideline. When a cave diver loses the guideline it is generally due to a lack of awareness. As we all know, awareness is our best friend while we are cave diving. We also know that when task loading goes up, awareness goes down. Cave instructors strive to have cave students develop muscle memory for the various skills utilized while cave diving, to cut down on task loading. As muscle memory for specific skills is developed, task loading decreases, and awareness increases.

advanced wreck diving philippines
Andy Davis, demonstrating ‘Lost Line’ protocol on a technical wreck diving course.

If you find yourself lost off of the line you need to stop and go through the procedure taught to you in all of your cave classes. The first thing to do when you become lost off of the line is to STOP moving, to avoid becoming even more lost. Reconstruct in your mind where and when you last saw the line. Was it on the floor? Was it on the ceiling? Was in the middle of the passageway? Was there flow in the section of cave where you last saw it? What was the bottom composition? What was the cave configuration in general? At this point you want to set up a search, a methodical search whereby you are not searching the same area over and over. Set up a search that searches a large area, rather than just a few feet from your present position.

During the cave classes you took the instructor had you conduct this exercise in simulated zero visibility. (This short article assumes the search will be made in zero visibility.) Some instructors use a blacked out mask, some have you close your eyes and dim the lights. Some instructors recommend you carry 2 safety reels on each cave dive. If we are indeed lost off of the line it is a very psychologically stressful situation. When deploying a safety reel in these circumstances your chances of dropping or jamming the reel increases. I have had a few students lose or jam the safety reel during this exercise, if they had no other reel they would likely never find the line.

Many instructors teach that you should knot the line of the safety reel every 10 feet or so. This is because when underwater in zero visibility it is very difficult to judge distance; the knots give us a reference to distance. I have seen many cave students conduct a search and never get more than a few feet away from their tie off point and consequently are unable to locate the line. They generally report to me that they thought they had travelled a greater distance during their search.

The tie off point needs to solid and prominent. The tie off itself needs to be very secure. Once the initial tie off is made I suggest the cave diver tug on it to ensure it stays in place. Then start the search. I suggest swinging in a pendulum type arc after deploying 10 feet or so of line. Once the cave diver has determined that the line is not within the 10 foot arc s/he then expands the search an additional 10 feet and continue with this process until the line is found.

technical wreck diving philippines
A technical diver rehearses ‘Lost Line’ drills on dry land. These drills are a common feature on both cave and technical wreck courses.

Hopefully your buddy has realized you are lost off of the line and is searching for you using the search techniques taught in his/her cave class.

Once you locate the line we are taught to tie the reel to the line and try to determine which way is the direction of the exit. If there is flow in the cave this generally is an excellent way of determining direction to the exit.

My suggestion is that you use the clip on your safety reel and clip it on the relocated line, on one side or the other of the safety reel indicating the direction you think the exit is, and proceed in that direction until the exit direction is confirmed. In most popular caves you will be able to determine this direction with one of the directional arrows within 100 feet.

Once your buddy finds your safety reel tied to the line you lost s/he can quickly determine that you have indeed found the line and also knows which direction you have travelled. This is one of the several reasons we put identifying marks or our name on our safety reels.

If after you swim and determine you are travelling in the wrong direction you turn around and go back to your safety reel and move the clip to the other side of the line indicating the new direction of travel.

Some cave divers are taught to use an arrow and not a clip. I think the clip is faster and requires less time, when time may be at a premium.

I suggest to cave divers that they practice this procedure periodically. Of course from a safety point of view you should have your buddy watch you to make sure you do not actually get lost off of the line.

For more details on expert Wreck Training in the Philippines, please check out my available courses;

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