Guidelines are the life lines within water filled caves. As long the visibility is good all is good and our vision will guide us toward the exit of the cave. It is when we lose all visibility that we are in need of the guideline to lead the way out of the cave, back to the surface and to ambient air. One of the leading causes of fatalities and near tragedies in cave diving involves the failure to follow a continuous guide line. This can occur when divers penetrate a cave without running a line from openwater to the permanent guideline or transfer from one line to another without installing a gap or jump line. To insure maximum safety, each segment of the dive should have a line installed that allows divers to follow it in total darkness. In addition, lines in a cave should be marked by directional arrows, personal non-directional markers such as “cookies” or cloth pin markers to indicate the exit path.
Permanent Lines
Permanent lines are installed permanently within a cave system. Their purpose is to facilitate the diving and exploration of a cave system and to insure a properly installed guide line is available for all visiting cave divers to use.
The permanent line installed in the cave system is often referred to as a main line, permanent line or a traverse line. The permanent line begins as close as possible to the cave exit but is at time cut back into the cave to avoid open water divers finding the line and going on cave diving. This line continues down the main passage to a specified termination point. The permanent line usually begins at some point beyond the cavern zone of a cave. A primary reel is used to travel to this line.
Navigation in Caves
In many caves there are more than one permanent line in that particular part of the cave making it a necessity to navigate inside the cave along the permanent lines where permanent intersections can be bound, referred to as a “T“. When a diver wishes to dive from one line to the next and is physically moving over to the other line this is referred to as a jump as long as leaving the end of one line going to the middle of another, leaving the middle of one line going to the end of another or leaving from the middle of one line and going to the middle of another. Leaving the end of one line and going to the end of another is referred to as a gap.
The exit has to be marked properly installing line arrows or personal line markers in order to secure that the exit has been marked and identified in a way it can be clearly understood in zero visibility and under high stress. It must be assured at all times that a continuous guideline is installed all the way to the openwater area of the cave entrance.
Gap and/or Jump Lines
A gap or jump line is one that is placed in passages that lead off from the primary line. Usually this line is placed as close to the permanent line as possible, but sometimes as far away as 30 feet/9 meters. At the junction where a gap/jump line is installed, line markers such as directional or non-directional should be installed indicating and marking our exit point.
Line Techniques
Skillful use of reels and the proper placement of lines is essential for efficient cave diving. The primary reel should always be tied off with a primary tie off at a point in open water where direct ascent to the surface is possible. This may be accomplished by beginning the line just in open water, providing the location allows divers to descend directly to the surface. There are numerous viewpoints on the merits of where to place the starting point but it must be initiated at a point that allows direct ascent to the surface.
Within and just inside the cavern zone, another safety tie off must be made called the secondary tie off. Should the primary tie off come loose the second one should keep the line in place close to the surface. If possible the secondary tie off could be done around 15 – 20 feet/4.5 – 6 meters depth, to aid and indicate safety and decompression stop depth in zero visibility.
When a line is being laid, tension must be placed on the reel to avoid “backlash” and protect the reel from jamming. When entering a cavern or cave and another team is exiting, yield the right of way as the exiting team has the right of way so they can leave easily.
A safety tie-off or placement must be made when a change in direction in the cave system occurs. Special care must be taken to avoid line traps. A line trap occurs when the line is allowed to be placed in an area where a diver cannot maintain physical contact with it during silt out. Ideally, the line should be placed in close proximity to the cave floor so divers can swim above it.
Line protocol requires awareness of the locations of the lines at all times. Always avoid swimming underneath the line. It may become tangled in your equipment or manifold. When crossing a line where your body will be in close proximity, use the reverse side of your open hand to keep the line away from your body. Do not grip or tug on the line while swimming. The proper hand contact to use is the “OK” sign. That is, form your fingers into an “O” and place them around the line. In silty areas keep in contact with both your buddy and your line. If a line becomes damaged, take the time to make repairs. This precaution may save your life. Avoid excessive wraps. Each time a line wraps over itself the structural strength is weakened considerably.
If an exiting cave diving team is encountered the exiting team has the right of way since they are low on air and on the last stretch of their cave diving journey. The only proper procedure to use one guideline in-between two teams is to discuss this procedure before the dive with all divers seeing the reel to be used and a personal marker to be used. The first team is installing the reel and continues the dive while the second team in is marking the exit side of the reel with a personal marker. The first team out is taking out only the line marker while the last team out is taking the reel out. If in any doubt if the other team already exited the reel and line must be left inside.
Line Markers
Line markers are used on guide lines to help you indicate directions in regards to where the exit is or to mark survey or science stations. Line markers are described as directional or non-directional markers. They consist of line arrows for directional line markers to clearly indicate the exit or direction to be taken toward the exit. Non-directional markers or personal markers are round “ cookies “ and clothespins used to mark locations or exits but have the advantage that they cannot cause potential confusion in regards to direction for other teams. Line arrows are triangle-shaped arrows with built-in slots to enable divers to attach them to the guide line. These are installed to indicate the direction of the nearest known exit. Often these will be marked with the distance from the cave entrance. Personal markers either directional or non-directional must be marked with your name or initials to identify them during the dive as reference points.
Line moving and removal
Guide lines installed in the cavern or cave area by other teams or permanent lines within the cave are not to be disturbed, touched, moved or removed by any individual. If lines are in the way for our own planned dive we may need to choose a different dive site. Our lines need to be placed in a way not to interfere with the other dive teams inside the cave as they do not know anything about the other lines close by. Our line needs to stay away from the other dive team’s line. We cannot use the same tie-off points as the other dive team’s line.
If lines need to be repaired or changed the proper procedure is to contact one of the cave safety officers who have been appointed by the training agencies to save guard the permanent lines installed within the caves. They will discuss the changes or repairs needed and will make them. After a repair or change is done the cave diving public will be informed about the changes or repairs. Many of the lines we see inside the caves are donated by training agencies and private individuals.