Greetings to John Phillips with his Marlin Spike nipple straightener
(09.01.16 MMD).  As an owner of several boats, I often find a marlin
spike very handy.  They are used on twisted rope line to aid in
splicing eyes and ends, as well as splicing two rope ends together, and
also to undo tight knots.

In the old sailing ship days they used the real, natural tapered spike
from a marlin fish.  No good sailor would be without one in his pocket!
In those days the art of tying knots and splicing rope was known as the
art of Marlinspike Seamanship.  Today we use bronze or stainless steel
"marlin spikes."

Nautically,
Brad Hunter