page_title: Distance line
section_title: Spools
hierarchical_section_title: Distance line / Equipment / Spools
caption_attribution_description: English: Injection moulded plastic diving spool with 30m of 1.5mm braided line and a double ender bolt snap
context_page_description: A distance line, penetration line, cave line 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. Guide lines are also useful in the event of silt out.
  Distance lines are wound on to a spool or a reel. 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, whereas a cave diver may use multiple reels of lengths from 25 ft to 1000+ ft.
  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.
context_section_description: Finger spools are a simple, compact low tech alternative to reels best suited to relatively short lengths of line. They are simply a pair of circular flanges with a hole in the middle, connected by a tubular hub, which is suitably sized to use a finger as an axle when unrolling the line. Line is secured by clipping a bolt snap through a hole on one of the flanges and over the line as it leaves the reel. Line is reeled in by holding the spool with one hand and simply winding the line onto the spool by hand. Spools are most suitable for reasonably short lines, up to about 50m, as it becomes tedious to roll up longer lengths. The small, compact size, and low cost make them useful for various purposes where long line is not required.
  Spools may be made from any material that is strong enough and suitable for underwater service, but engineering thermoplastics are most common.
caption: Injection moulded plastic diving spool with 30m of 1.5mm braided line and a double ender bolt snap
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