Maritime slang for being bent over a cannon and
whacked with
a
cane. This was a common
punishment in the
British Royal Navy
for a while.
Other sources suggests that the punishment is to tied to the barrel of
a cannon while it is fired four or five times. This seems rather
impractical, since you'd be wasting a lot of ammunition. Unless of
course it was done during an actual battle, but that seems rather
awkward as well.