grapnel

A grapnel is a type of anchor or grappling device consisting of a short shank with several curved tines (or arms) that spread outward to snag onto underwater features or submerged objects. The most common form is the multi-tined grapnel anchor, designed to catch on seabed material such as rock, debris, or vegetation when tension is applied.

Grapnels are used in maritime salvage, temporary mooring, and recovery operations. They are deployed on a line or chain and lowered into the water; as they sink and the vessel moves, the tines are intended to hook under or into the target material. Retrieval is accomplished by hauling in the line, bringing the grapnel with the hooked object to the surface. Small boats typically employ four-tine configurations, while larger operations may use bigger or more robust versions.

Performance depends on the seabed type. Grapnels work best in soft sand, mud, or cluttered bottoms where the tines can catch, but they are less effective on hard rock or compact gravel and can foul with weed, wreckage, or tangled debris. Their efficiency is also influenced by the number of tines, weight, and the strength of the hauling line.

Historically, grapnels have been used for centuries in naval operations, salvage, and civil engineering contexts to recover sunken gear or secure temporary holds. The term is sometimes conflated with grappling hooks used for climbing or boarding, though those devices are distinct tools with different purposes.