Sea anchor
Modern commercial sea anchors are usually made of cloth, shaped like a parachute or cone, and rigged so that the wider end leads and the narrower end trails. When deployed, this type of sea anchor floats just under the surface, and the water moving past the sea anchor keeps it filled. Some varieties are cylindrical, with an adjustable opening in the rear that allows the amount of braking to be adjusted when deployed.
Offshore embedded anchors
Anchor piles are hollow steel pipes that are either driven or drilled and grouted into the seabed, similar to pile foundations commonly used in offshore fixed structures. The figure shows the different installation methods whereby the driven steel tube is driven mechanically by a driving hammer, whilst the cast in-situ grouted pile is inserted into an oversize borehole constructed from a rotary drill and subsequently grouted in cement. Both methods are commonly used offshore depending on the geophysical and geotechnical properties of the seabed.