There was some old Captain of the Line, back in the 1700's who was a God fearing man, and he was appalled at the amount of superstition in the Navy. So he decided to dispel the myths of the stupid Sailors, and encourage them to put their faith in God. He had a brand new Ship, which he decided to call "Friday" (after the unluckiest day to set sail on) The ship was launched on Friday the thirteenth, with no naming ceremony.
He also had a few cages of rabbits ( Anathema to Sailors) for the Galley stewpot, all in an attempt to prove that superstition was irrelevant as long as you had a good ship, a good crew, a good Captain, and good wind. As the ship set sail from Portsmouth Harbour, on a fine Spring morning, the Captain
was heard to be actually whistling from his quarterdeck, as she was piloted out into the Solent. Off she sailed, and was never seen or heard of again. It's one thing not to be superstitious, but quite another to deliberately court bad luck.
Especially at Sea.
Where I'm reliably informed, "Worse things happen".
I have no citation for this story, and while it might be a load of old bollocks, if I had been a Sailor, signed on to the Friday, I would have made sure I jumped ship on Thursday bloody afternoon, and signed on to another Ship, first thing Saturday morning Matey. Aaargh!