French Bowline Knot. Some consider that a French bowline is the same as a Portuguese bowline, i.e. a bowline with two loops that can be used as a bosun's chair. A different knot is however also known as a French bowline. Uses: Apart from being used as a harness, the French Bowline has other practical uses. For example, it can be used to join two ropes together for fastening mooring lines; for rigging work; and it can also be used as makeshift shackles if necessary. | Nots