What is "reef knot"

Reef \Reef\, n. [Akin to D. reef, G. reff, Sw. ref; cf. Icel. rif reef, rifa to basten together. Cf. Reeve, v. t., River.] (Naut.) That part of a sail which is taken in or let out by means of the reef points, in order to adapt the size of the sail to the force of the wind.

Note: From the head to the first reef-band, in square sails, is termed the first reef; from this to the next is the second reef; and so on. In fore-and-aft sails, which reef on the foot, the first reef is the lowest part.
--Totten.

Close reef, the last reef that can be put in.

Reef band. See Reef-band in the Vocabulary.

Reef knot, the knot which is used in tying reef pointss. See Illust. under Knot.

Reef line, a small rope formerly used to reef the courses by being passed spirally round the yard and through the holes of the reef.
--Totten.

Reef points, pieces of small rope passing through the eyelet holes of a reef-band, and used reefing the sail.

Reef tackle, a tackle by which the reef cringles, or rings, of a sail are hauled up to the yard for reefing.
--Totten.

To take a reef in, to reduce the size of (a sail) by folding or rolling up a reef, and lashing it to the spar.

n. A knot used to securely tie two pieces of rope together, or to reef sails

n. a square knot used in a reef line [syn: flat knot]

The reef knot, or square knot, is an ancient and simple binding knot used to secure a rope or line around an object. It is sometimes also referred to as a Hercules knot. The knot is formed by tying a left-handed overhand knot and then a right-handed overhand knot, or vice versa. A common mnemonic for this procedure is "right over left; left over right", which is often appended with the rhyming suffix "... makes a knot both tidy and tight". Two consecutive overhands of the same handedness will make a granny knot. The working ends of the reef knot must emerge both at the top or both at the bottom, otherwise a thief knot results.

Although the reef knot is often seen used for tying two ropes together, it is not recommended for this purpose because of the potential instability of the knot, and over-use has resulted in many deaths (see #Misuse as a bend).