Abstract: A releasable guidepost extension is used on the seabed together with a bottom fixed guidepost part. These parts make up a guidepost for use during the lowering of a component from the surface of the water to a subsea structure. The guidepost part includes an upward (in use position) projecting end designed for engagement with a lower (in use position) end of the guidepost extension. The guidepost extension is loosely connected to the bottom fixed guidepost part via a pin and socket part on respective ends. A gap, or clearance, exists between the pin and socket part in the longitudinal direction, and at least one friction forming device arranged in the gap on either the pin part or in the socket part. The friction forming device does not get in contact, or engaged, with the other part unless the guidepost extension is subjected to a lateral force.