In the early days of cave diving, guideline reels were not available for purchase and divers made their own using anything they could find. Cave diving pioneer Woody Jasper used a medical tape spool with cover to hold a short length of line for use as a gap reel. North Florida cave diver Bill Hogarth Main popularized using smaller electrical wire spools for safety and jump reels. Today, purpose built finger spools are more ergonomically designed and constructed from more durable materials than the original homemade solutions. The holes in the side allow for clipping a double ended snap anywhere along the perimeter of the finger spool to keep the line tight when not in use. Small and low-profile, a finger spool fits nicely out of the way in a pocket or clipped off to a D-ring. The larger finger spools are also an alternative to reels for shooting lift bags and surface marking tubes.