The folks who go to sea are a brave bunch to my way of thinking. They encounter so many things they cannot control. Storms, icebergs, pirates are only a few. No wonder they have superstitions to try to keep them safe. Some of them are:
No bananas on board. This is possibly because they rot so fast
Tossing a coin into the ocean before a voyage will guarantee a safe trip.
Protect the albatross. It is supposed to be the home of the spirit of a sailor who died at sea.
A female on board brings bad luck. I do not know why.
Whistling on board calls winds and storms
Red sky in the morning sailor take warning. Red sky at night sailors' delight. It foretells the weather.
Place a coin under the mast for a safe voyage.
The ship's bell marks watch times and time in general. It also drives away evel spirits to protect thew crew.
Tattoos were made to represent designed to bring good luck to the sailor.
Rats deserting the ship was a bad sign. Fire, leaks, or the ship falling apart are reasons.
My mind describes the Kraken as a giant octopus.
Mermaids lured sailors to their deaths with their beauty.
Phantom ships like The Flying Dutchman struck fear into sailors who feared they would be forced to man that ship.
Losing a hat overboard means a long voyage.
Of course this sis a partial list. Do you have a favorite to share?