In the 16th and 17th centuries, everything had to be transported by<br />ship and it was also before commercial fertilizer's invention, so large<br />shipments of manure were common. It was shipped dry, because in dry form<br />it weighed a lot less than when wet, but once water (at sea) hit it, it<br />not only became heavier, but the process of fermentation began again, of<br />which a by product is methane gas.<br /> <br /> As the stuff was stored below decks in bundles you can see what could<br />(and did) happen. Methane began to build up below decks and the first<br />time someone came below at night with a lantern, BOOOOM! Several ships<br />were destroyed in this manner before it was determined just what was<br />happening.<br /> <br /> After that, the bundles of manure were always stamped with the term<br />"Ship High In Transit" on them which meant for the sailors to stow it<br />high enough off the lower decks so that any water that came into the<br />hold would not touch this volatile cargo and start the production of<br />methane.<br /> <br /> Thus evolved the term "S.H.I.T " (Ship High In Transport) which has<br />come down through the centuries and is in use to this very day.<br /> <br />If you didnt know, now you do. 
