Knots to Know: Square knot

The square knot is useful for binding two identical lines or two ends of the same line around an object for light duty, such as when reefing a sail. You can also use a square knot when furling sails, tying cargo straps and hanging up clothes to dry.  

If lines are of different diameter or you need a more reliable binding knot, use a sheet bend.

To tie the square knot:

1. Start by holding an end of the line in each hand.
2. Grab the working end in one hand over the line in the other hand, creating a bight like when tying your shoes.
3. Transfer the working end to your second hand. Repeat in the opposite direction with a line in your second hand over the line in your first.
4. Pull all four slack lengths of line to tighten.
5. If the knot looks like two interlocking loops with both bitter ends on the same side of the knot and both ends of each line exiting in the same direction, you’ve done it right.

Remember to switch each line to the other hand. This ensures that the bitter ends wind up on the same side as their standing lines, otherwise the knot will not hold. It doesn’t matter whether you start on the left or right as long as you tie the second overhand knot the opposite way from the first.

To untie, collapse the knot using one hand and the weight of the reefed sail to open it. Or push all four slack ends together to loosen it.

For other useful knots, check out Knots to Know. A new knot will be added every month.