Page 82 - Mario Bigon "The Morrow Guide to Knots"

The Portuguese bowline is
used by Portuguese sailors for
tying the anchor. It is also
known as the caulkner's
bowline and is used to
support a man who has to
work from a suspended
position. In this case, the first
loop passes around the man's
back; then having adjusted
the two loops. he can sit on
the second. The Portuguese
bowline is useful for
reinforcing the hold on an
object. particularly if it is
heavy. It can be formed with
two or more loops, the more
loops the stronger the knot.
Method
Form a turn on the standing
part of the loop with the
casting method described on
page 72 (1). Pass the end
behind the standing part and
form asecond loop (2). Insert
the end into the turn (3); then
pass the end behind the
standing part again and insert
it back into the turn (4). To
tighten the knot, take hold of
the end, and the two loops
with the left hand and pull the
standing part with the right
hand (5).