Over the centuries seagoing bottles have carried a remarkable variety of messages—some sad, some happy, and many that tie in with historical events.
The most widespread and valuable use of sea bottles has been to trace ocean currents so that ships may avoid an opposing current and take advantage of a favorable one. One dramatic example of this use was made by the Colonies’ deputy postmaster general, Benjamin Franklin, before the Revolutionary War. Puzzled as to why British mail packets usually took a week or two longer than Yankee ships to make the Atlantic crossing, Franklin talked to Yankee whaler captains. He found that bottles loosed in the Gulf Stream arrived in North America faster than those simply thrown in the sea anywhere. Thereafter, British ships followed that current.
About 1860, the British Navy began issuing printed forms for ships’ officers to drop overboard in bottles. These forms, still used by the U.S. Navy and U.S. Coast Guard, give excellent information about currents.
American government scientists use bottles to tip off fishermen as to where and when they may find cod and haddock. The eggs of these fish float on the surface and bottles cast among them serve as telltale floats.
Bottles have joined the fight against the menace of sludge oil in the sea. The crude oil carried by tankers leaves a sticky, tar-like residue that ships must get rid of by “blowing off their tubes.” Often this unsightly and contaminating mass floats on the surface only until it can drift to shore on some current. By making bottle studies, it is hoped oceanographers can find safe places where sludge might be deposited.
Fragile as it may seem, a well-sealed bottle is one of the world’s most seaworthy objects. It will bob safely through hurricanes that often sink large ships. For most practical purposes, glass lasts forever. Bottles as good as new were pulled up from a ship sunk 250 years ago.
The speed of a drifting bottle varies, of course, according to wind and current. A bottle adrift in quiet waters may not move a mile in a month. Another caught up by the Gulf Stream may bowl along at a brisk pace and travel one hundred miles a day.
There is always an excitement in wondering where a bottle will come ashore. If you live near an ocean beach or visit one while on vacation, put a message in a heavy bottle and cork it tightly. Then have someone row you out in a boat about fifty feet from shore and drop your bottle overboard. One day, long after you have almost forgotten about your adventuring bottle, you may hear from a new friend who has found it!