I don't know if this is the "real name" of this hitch
or not, but it's useful anyway. It was taught to me at
a BSA aquatics base, and I've found it useful a few
times since then.
Basically, this is a hitch that allows you to snug up
the loop against a pier or other post. At the same time,
it is easily untied with a simple pull.
To tie, toss the rope around the post. On the loose end
of the rope, form a loop. Push the attached end through
the loop to form another loop. Finally, push a bight
of the remaining loose end through the second loop.
Pulling on the attached end will straighten it out, and
the attached end can snug up against the post. The
loose end can be undone by pulling on the very end.
_________
/ \
/ _____ \
/ / \ \
/ / ##### \ \
/ / ####### \ \
/ / ######### \ \ ______ ______
\ \ ######### \ \/ \/ \
\ \ ####### \ / __ / __ \
\ \ ##### \/ / \/ / \ \
\ \_________ / /\ / /\ / /
\ \/ / \/ / \/ /
\_________ \ /\ \ /\ / /
\ \/ \ \/ \/ /
/\ \ /\ \ / /\
/ \ \/ \ \/ / \
/ /\ / /\ \ /\ \
\ \__/ / \ \/ \ \
\ /\ /\ \ / /
\______/ \/ \ \/ /
\ / /\ / /
\/ / \/ /
__/ /\__/ /\______________
loose | / /
end |____/\______/\________________