Nape piercing
Somewhat less common are surface anchors, commonly made from surgical implant-grade titanium. A surface anchor has two parts: a base or foot which is inserted under the dermis during the piercing process and which incorporates a stem exposed to the surface, and a decorative disc or ball of jewelry which typically appears flush with the surface of the skin. Surface anchor nape piercings are most commonly found placed symmetrically on either side of the spine at the nape.
Anchor
Permanent anchors come in a wide range of types and have no standard form. A slab of rock with an iron staple in it to attach a chain to would serve the purpose, as would any dense object of appropriate weight (for instance, an engine block). Modern moorings may be anchored by augers, which look and act very much like oversized screws drilled into the seabed, or by barbed metal beams pounded in (or even driven in with explosives) like pilings, or by a variety of other non-mass means of getting a grip on the bottom. One method of building a mooring is to use three or more conventional anchors laid out with short lengths of chain attached to a swivel, so no matter which direction the vessel moves, one or more anchors will be aligned to resist the force.