This legend goes back to the London of 1664, when Charles II was King of England. A ship’s master, returned from a long cruise, told him a sea story he couldn’t believe.
“Fish that fly like birds?” the Merry Monarch exclaimed. “I have my doubts!”
“Nay, sire, it is true,” said Sir William Killigren, colonel of the new British Marine regiment raised that year. “I have myself seen flying fish many a time in southern waters. I vouch for the truth of this strange tale, your Majesty.”
The King thought it over. At last he turned to Samuel Pepys, the Secretary of the Admiralty.
“Mr. Pepys,” he said, “no class of our subjects hath such knowledge of odd things on land and sea as our Marines. Hereafter, when we hear a yarn that lacketh likelihood, we will tell it to the Marines. If they believe it, then we shall know it is true.”