"guide line" redirects here. For other uses, see guideline (disambiguation).
Distance line
50 metres of line on a reel
Other names
guide line, cave line, dive reel, wreck line, penetration line
Uses
Used to guide divers back to a specific point
Related items
Jackstay, jump line, search line, down-line, upline, messenger line
Cave diving guide line reel
A distance line, penetration line, cave line, dive reel or guide line is an item of diving equipment used by scuba divers as a means of returning to a safe starting point in conditions of low visibility, water currents or where pilotage is difficult. They are often used in cave diving and wreck diving where the diver must return to open water after a penetration when it may be difficult to discern the return route.[1][2] Guide lines are also useful in the event of silt out.[3]
A cave diver running a distance line into the overhead environment to facilitate a safe exit
Distance lines are wound on to a spool or a reel for storage, and are laid in situ by unrolling.[4] The length of the distance line used is dependent on the plan for the dive. An open water diver using the distance line only for a surface marker buoy may only need 50 metres (160 feet), whereas a cave diver may use multiple reels of lengths from 25 ft (7.6 m) to 1000+ ft (300 m).
Reels for distance lines may have a locking mechanism, ratchet or adjustable drag to control deployment of the line and a winding handle to help keep slack line under control and rewind line. Lines are used in open water to deploy surface marker buoys and decompression buoys and link the buoy on the surface to the submerged diver, or may be used to allow easy return navigation to a point such as a shotline or boat anchor.
The material used for any given distance line will vary based on intended use, nylon being the material of choice for cave diving.[4] A common line used is 2 mm (0.079 in) polypropylene line when it does not matter if the line is buoyant.
The use of guide line for navigation requires careful attention to laying and securing the line, line following, marking, referencing, positioning, teamwork, and communication.[3]
^Cite error: The named reference Exley was invoked but never defined (see the help page).
^Cite error: The named reference Guideline 2 was invoked but never defined (see the help page).
^ abCite error: The named reference Guideline 3 was invoked but never defined (see the help page).
^ abCite error: The named reference Guideline 1 was invoked but never defined (see the help page).
A distanceline, penetration line, cave line, dive reel or guide line is an item of diving equipment used by scuba divers as a means of returning to a...
Euclidean geometry, the distance from a point to a line is the shortest distance from a given point to any point on an infinite straight line. It is the perpendicular...
Straight-linedistance is formalized mathematically as the Euclidean distance in two- and three-dimensional space. In Euclidean geometry, the distance between...
In mathematics, the Euclidean distance between two points in Euclidean space is the length of the line segment between them. It can be calculated from...
would not travel well in cages, as they fight if confined. Distance Geodesic Great-circle distance Allen, Robert (2008). Allen's Dictionary of English Phrases...
perpendicular distance between two objects is the distance from one to the other, measured along a line that is perpendicular to one or both. The distance from...
shortest line segment joining Line 1 and Line 2: d = ‖ c 1 − c 2 ‖ . {\displaystyle d=\Vert \mathbf {c_{1}} -\mathbf {c_{2}} \Vert .} The distance between...
considered the theoretical line to which points on any horizontal plane converge (when projected onto the picture plane) as their distance from the observer increases...
A distance transform, also known as distance map or distance field, is a derived representation of a digital image. The choice of the term depends on the...
Boeing 707 and Douglas DC-8 followed, and much long-distance travel was done by air. The Italian Line's SS Michelangelo and SS Raffaello, launched in 1962...
a line segment between any two points has the same length as a grid path between those points rather than its Euclidean length. The taxicab distance is...
integers can be seen as a distance from zero on the number line.[clarification needed] For binary strings a and b the Hamming distance is equal to the number...
Distance measures are used in physical cosmology to give a natural notion of the distance between two objects or events in the universe. They are often...
length of a line segment is given by the Euclidean distance between its endpoints. A closed line segment includes both endpoints, while an open line segment...
multisport race consisting of swimming, cycling, and running over various distances. Triathletes compete for fastest overall completion time, racing each...
comoving distance and proper distance (or physical distance) are two closely related distance measures used by cosmologists to define distances between...
main methods are based on line transects or point transects. In this method of sampling, the data collected are the distances of the objects being surveyed...
Suburban Railway halt at this station. All Harbour Line services are slow services. Long Distance indicates that trains other than local trains halt at...
The Mahalanobis distance is a measure of the distance between a point P {\displaystyle P} and a distribution D {\displaystyle D} , introduced by P. C...
Distance education, also known as distance learning, is the education of students who may not always be physically present at school, or where the learner...
electronics, especially radar terminology, slant range or slant distance is the distance along the relative direction between two points. If the two points...
hyperfocal distance is a distance from a lens beyond which all objects can be brought into an "acceptable" focus. As the hyperfocal distance is the focus...
Global Information
