Mares Cave/Finger SS317 Coated Spool: Review, Features, and Scuba Diving Opinions (2026)

At a depth of twenty meters, towards the end of a drift dive along a slope exposed to surge, deploying your decompression float requires movements of surgical precision. In this transitional zone where currents accelerate and attention must remain focused on buoyancy, a poorly designed or slippery finger spool can turn a routine maneuver into an unnecessary moment of stress. The Mares Cave/Finger SS317 Coated Spool was designed specifically to meet this requirement for mechanical simplicity and secure grip underwater.

The Mares Cave/Finger SS317 Coated Spool belongs to the family of spool-type guidance equipment (30 meters marked), designed for deploying decompression floats (DSMB) and safety marking. Its mechanical design prioritizes component reliability and ease of control underwater.

Its machined construction allows for smooth handling with dry gloves or thick neoprene. The spacing of the spools and the line guidance have been designed to minimize the risk of derailment during rapid deployment.

The integrated line offers a usable length of 30 meters, clearly marked. The high-strength braided line offers excellent resistance to abrasion on rock and oxidized metal.Visually, the contrasting color of the line makes it easier to spot in waters with a lot of particles or during twilight decompression stops. The end of the line has a reinforced termination for a secure attachment.

The ergonomics of a spool are judged by its ability to rotate freely without jerks. The side flanges provide sufficient support to control the braking with your thumb on the edge, thus preventing the spool from spinning out of control during a rapid ascent of the DSMB. The central hole allows you to insert a finger while wearing thick gloves without the risk of jamming.

Imagine a wood lathe operator guiding their chisel with a smooth motion across a rotating piece. Underwater, the diver uses the pad of their thumb against the side of the spool in exactly the same way, regulating the tension of the line so that the drogue rises straight without creating a loose loop.

The Mares Cave/Finger SS317 Coated Spool is manufactured using top-quality marine materials designed to withstand the effects of salt, hydrocarbons, and UV radiation. The frame can withstand impacts against the boat hull or rocky walls without damage.

Precise machining of the surfaces eliminates any parasitic axial play, ensuring smooth and consistent rotation over time.

The peripheral anchor points allow the line to be securely locked in place at rest with a double-ender carabiner to prevent any accidental unwinding in the thigh pocket.

The price point of the Mares Cave/Finger SS317 Coated Spool reflects the quality of its construction and its mechanical robustness. It is a piece of equipment designed to last for years of intensive diving without weakening, provided it is simply rinsed with fresh water after each dive.

The Mares Cave/Finger SS317 Coated Spool establishes itself as a solid and effective reference in its category. Whether you are looking for a reliable signaling tool for drift dives or a navigation reel for your advanced dives, it provides a clear and proven technical solution.

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Consult our reel and spool comparator and our complete catalog of diving equipment to compare this model with all the references on the market.