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.
Traditional climbing
When a climber has reached the top of a climb an anchor must be set up to allow the leader to bring up the seconder safely. An anchor has a number of different components which should be put together in a redundant way to make the anchors safe.In some cases a traditional climb may be too difficult or there might not be enough time to complete the climb before dark. The lead climber may decide to abort the climb (or "bail") and descend to the ground before reaching the top. To do this an anchor is set up mid-climb and whatever protection that is required to ensure a safe descent is left on the rock after the climbers abseil to the ground.A number of types of rock are climbed on each with a varying degree of suitability for traditional climbing. Some examples are sandstone, granite and limestone.