Anchors and Anchor Parts
Forfjord - Seadog - Halibut & Sea Anchors

Illustration of Sea Anchor
Sample of Sea Anchors

The anchor parts
The shank is the stem of the anchor in which direction is pulled to set (bury) the anchor.
The crown connects the various parts of the modern anchor.
The stock turns the anchor into an attitude that enables the flukes to dig into the sea bed.
The tripping ring is used for the optional tripping line: by pulling the tripping line, the anchor will break out.
The flukes will be buried into the seabed. The very tip of a fluke is sometimes called the bill.
The fluke style anchor, named due to its large flukes, uses a stock at the crown to which two large flat surfaces are attached. The flat surface (the flukes) hinge changing the angle to the stock. On some designs like the Fortress, the flukes angle can be optimized for different bottom types.

The hinged design allows the flukes to dig in while the shank aligns with the pull. Its light weight and compact flat design make it easy to handle. Storing on an anchor roller is common.

The fluke anchor has difficulty penetrating kelp and weed-covered bottoms due to its lightness and flat shape which can skate over the bottom.

Once set, the anchor tends to break out and reset when the direction of force changes dramatically, such as with the changing tide, and on some occasions it might not reset but instead drag.

Modern designs such as the Fortress, are light and can be dismantled for stowage below
Sea anchors can be used by vessels of any size, from kayaks to commercial fishing vessels, and were even used by sea-landing naval Zeppelins in World War I. While the purpose of the anchor is to provide drag to slow the vessel, there are a number of ways this can be used:

The first, and probably most well known use, of the sea anchor is to aid vessels in heaving to in heavy weather. A boat that is not kept bow- or stern-on to heavy seas can easily be rolled by the action of the waves. By attaching the sea anchor to a bridle running from bow to stern, the boat can be held at any angle relative to the wind. This is useful in sailboats in conditions too windy to use the sails to maintain a heading, and in motor vessels that are unable to make sufficient headway to maintain steerage.

Sea anchors also reduce the speed at which a vessel will drift with the wind. Often sold as drift anchors or drift socks, sea anchors are used in fishing vessels to hold them relatively stationary relative to the water to allow a certain area to be fished, without having to use the motor.

A sea anchor can provide directional control of a sailboat in the case of a steering failure. By towing a sea anchor from a bridle off the stern, the direction of the boat can be controlled on a running course.

A sea anchor can be used to control the speed of a sailboat, in cases where delicate handling is required in high winds.

A sea anchor can be used behind a towed vessel to maintain tension on the towing line, and prevent the radical side-to-side motion exhibited by some vessels under tow.

Sea anchors may also be used as anchors to allow warping of a vessel in deep water.