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.
Anchor
Chain rode is relatively heavy but resists abrasion from coral, sharp rocks, or shellfish beds which may abrade a pure rope warp. Fibre rope is more susceptible to abrasion on the seabed or obstructions, and is more likely to fail without warning.