The latest piece in The Supernatural Writings of Stuart Palmer comes from the same issue as the last one—and for some reason, both of them are under pen names.
An UNEARTHLY Stowaway is another "true" eerie tale, written under the name "Theodore Orchards." The first mate of a barque enroute from Liverpool to Canada sees a strange man in the chart room. The man leaves a written message to "Steer to the Northwest," then disappears. No stowaway is found on board. The captain decides to obey the message, resulting in the rescue of everyone aboard an icebound wreck.
The (uncredited, as usual) source for this tale appears to be an account by the social reformer, abolitionist, US Congressman, and Spiritualist, Robert Dale Owen (1801-1877). He presents the tale as true, in his 1860 book, Footfalls on the Boundary of Another World (the story is called "The Rescue," and starts on the bottom of page 333). Owen learned the story secondhand from a friend of the first mate in 1859, many years after the event supposedly happened.
I was tickled to read this story, because I'd come across it before, as an episode of the 1950s anthology TV series, Telephone Time (sponsored by Bell Telephone). It's called "The Vestris," and it features Boris Karloff! The episode is on YouTube, at least as of this writing. The episode also includes some amusing ads for the telephone, as well as a teaser for the following week's episode, which featured Jessica Tandy and Hume Cronyn.
Note that the Telephone Time host does credit the story to Robert Dale Owen, even though the version shown is rather different from Owen's account: it's the captain's wife who sees the ghostly apparition, rather than the first mate. Other details vary, as well.
"The Vestris" also served as the "backdoor pilot" to the (never aired) Boris Karloff-hosted series The Veil, which I wrote about some time ago. My article includes YouTube links to all the episodes, which hopefully all still work. I believe you can find the series on the Internet Archive, as well. If you enjoy "true" stories of the supernatural, you should check it out.