Diving shot

See also: Decompression practice and Decompression equipment
Diving shot
View from below of buoy clipped to reel of diving shotline deployed in fairly shallow water (about 20m). Most of the 100m line is still on the reel
Buoy and reel of diving shotline deployed
Other names
  • Diving shot-line
  • Shotline
UsesMarking a dive site and providing a stable reference for the divers to descend and ascend
Divers ascending and decompressing on a basic shotline: Weight, and float connected by a line of fixed length
Bottom tensioned shotline: The line passes through a ring at the weight and is tensioned by a small float, often a small lift bag which can later help lift the shot as the air expands.
Top tensioned shotline: The line passes through a ring at the float and is tensioned by a smaller weight hanging from it. This weight may be hooked to the main part of the line by a sliding clip to restrain it from swinging.
A shotline with a lazy shot - a second float with a short weighted line tethered to it at just below the depth of the deepest long decompression stop.
A shotline with a decompression trapeze - a series of crossbars suspended from a float at each end and ballasted as necessary, tethered to the main shotline.
A shotline with spar buoy to reduce vertical movement near the surface in a seaway

A diving shot line, shot line, or diving shot, a type of downline or descending line (US Navy),[1] is an item of diving equipment consisting of a ballast weight (the shot), a line and a buoy. The weight is dropped on the dive site. The line connects the weight and the buoy and is used by divers to as a visual and tactile reference to move between the surface and the dive site more safely and more easily, and as a controlled position for in-water staged decompression stops. It may also be used to physically control rate of descent and ascent, particularly by surface-supplied divers.

A "lazy shot" is a shot which is suspended above the bottom. It may be tethered to the main shot line at a convenient depth. It is used for decompression and frees the main shot line for other divers. The lazy shot's line does not need to be longer than the decompression depth and is often only deep enough for the longer stops. It only needs a weight heavy enough to provide diver buoyancy control and sufficient buoyancy to avoid being dragged down under reasonably foreseeable circumstances.[2]

  1. ^ Cite error: The named reference USN training was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference shots and deco rigs was invoked but never defined (see the help page).