Sailors and pirates tended to be very superstitious - that is, they had a fear of the unknown and used it to explain misfortune (bad things that happened).

Living and working on a ship in the middle of the seven seas was a very dangerous job. Over time they invented stories and rules to help them believe they could avoid terrible fates.

Pirate School Fear

Below are just some of the many superstitions of sailors and pirates.

A shark following the ship is a sign that a death of a crew member was going to happen.

Dolphins swimming with the ship brings good luck. 

The seabirds were thought to carry the souls of dead sailors and it is considered bad luck to kill one. But if you saw one you had good luck.

No Whistling on Board
Sailors have long held the belief that whistling or singing into the wind will whistle up a storm.

A pierced earlobe on a sailor meant that he had sailed around the world or had crossed the equator. Superstitious sailors wore gold hoop earrings because they believed it brought good fortune. Some even believed that the gold would prevent the wearer from drowning.

Manta Rays
Sailors believed these sea creatures could attach themselves to a ship’s anchor and drag her under the waves to Davy Jones’ Locker.

Davy Jones
Davy Jones is the evil spirit of the sea. He was one that leads the evil spirits of the deep, and is often seen in various shapes, resting and waiting in the rigging before wild storms or shipwrecks and other disasters. He was there to welcome new sailors to their watery graves. 

Davy Jones’ Locker
The bottom of the sea; the mythical resting place of drowned sailors and ships.

This list isn't a full one. There are many more sailor superstitions that would have guided sailors and pirates. See if you can find some more. With science and underwater research, we know that these are stories and not real. But many people today are superstitious - did you know that it's thought to be unlucky to walk under a ladder, or have a black cat cross in front of you?