Page 32 - Eric C. Fry - Knots and Ropework

The initial movements to form this knot are as for the bowline
16 1 Knot 1 5, Figs 1 to 4), except that a bight of the rope is used
(Fig 1),
Bowline on The variation occurs from this point onwards, sufficient of the
bight being drawn up through the loop, before being passed down
a Bight over the two main bights and returned up the back of the knot to
its position around the standing parts and/or tail end. This knot
can be used as a man harness similar to that shown in Knot 11,
by making it in the centre of a long rope, with two standing parts
and the sizes of the bights adjusted as previously described.
If the initial bight of Fig 1 is passed around the standing part and
back down through the loop (as with the tail of a bowline), the
knot becomes a double bowline (not illustrated).