A knot that dates back to antiquity
The purpose of the sling knot, also known as the bottle, jar or neck knot, is to add a handle to a bottle to make it easier to hang or carry. It dates back to Roman times, hence the name jar knot. In more recent times, it could also be used by cowboys to improvise a halter or bridle.
In order to work, the neck must have a collar to lock the knot. This last one requires a little practice to make it quickly. There is no doubt that in the summer season, the aperitifs on board allow to practice it enough!
The sling knot step by step
Making a lark's head
Double a small piece of about a meter to obtain a ganse. Then fold the braid to form a lark's head.
Create a slot
Pass the right loop over the left loop to create a slot.

Twist the slot
Twist the slot by passing the right side over the left side.

Pass the bottom of the braid through the slot
Grab the bottom of the starting braid, which forms the base of a small triangle below the slit, then pass it under the left strand of the triangle and through the slit and onto the right strand of your figure.

Bring the right strand to the left
Fold the top right single knot underneath to the bottom left.

Bring the left strand to the right
Fold the top left single knot over to the bottom right.

Prepare the passage of the bottle
Shape the center of the knot to fit the neck of a bottle.

Tighten the knot
Carefully tighten the knot around the bottle so that it can be hung.

It's up to you!