Messages in bottles may not be the fastest form of communication, but they have been around for a very long time. One of the first known messages in a bottle was released by Greek philosopher Theophrastus in 310 B.C. It is thought that Theophrastus was conducting an experiment using water currents to prove that the Mediterranean Sea was formed by the Atlantic Ocean.

Messages in bottles have been used in more recent times, too. In 2005, a group of migrants shipwrecked off the coast of Costa Rica sent a cry for help by enclosing a message in a bottle. They managed to tie the bottle to a long line on a fishing boat as it passed. The bottle was received, and the people were rescued.

So why do people send messages in bottles? Glass may be very fragile, but bottles do well at sea.

They are buoyant, which means they don’t sink. They can bob on the surface of the ocean for years and years. Also, even if immersed in water, glass does not tend to biodegrade or weather like other materials might.

In order to give you an idea of how well glass bottles can survive at sea, let’s talk about the Titanic. Wine and champagne bottles have been recovered from the wreckage of the ship, which sunk in 1912. Although the Titanic sunk nearly a century ago, not only did the bottles survive, but rumor has it some of the bottles still have bits of wine and champagne inside.

So, if you find yourself stranded on an island, is a message in a bottle the way to go? There is no way to predict where a message in a bottle will end up or how long it will take to get there.

A bottle’s course relies on the ocean currents. It can’t hurt to launch your message in a bottle and hope for the best, but in the end, you may be in for a very long wait.