In the 16th and 17th centuries, everything had to be transported by ship
and it was also before commercial fertilizer's invention, so large
shipments of manure were common.

It was shipped dry, because in dry form it weighed a lot less than when
wet, but once water (at sea) hit it, it not only became heavier, but the
process of fermentation began again, of which a by-product is methane gas.


As the stuff was stored below decks in bundles you can see what could
(and did) happen. Methane began to build up below decks and the first time
someone came below at night with a lantern, BOOOOM! Several ships were
destroyed in this manner before it was determined just what was happening.


After that, the bundles of manure were always stamped with the term "Ship
High In Transit" on them which meant for the sailors to stow it high
enough off the lower decks so that any water that came into the hold would
not touch this volatile cargo and start the production of methane.

Thus evolved the term "S.H.I.T." (Ship High In Transport) which has come
down through the centuries and is in use to this very day. You probably
did not know the true history of this word.

Neither did I. I thought it was a golf term.