Does the naval record give height and eye colour?
5 ft 3 ¾ in. He might need to have shrunk! Hazel eyes.
Arms were indeed covered in tattoos!
Is he the James Glen born 1887 with a CR10 card in the British merchant seamen records (1918)

They usually have a photo (not of the arms though!)
Baptisms on ancestry of Louis Henry and Hilda Sophia at Bedfont.
Father Henry James in ASC, then Labourer.
What was he up to in Southampton in 1909?
If that is the correct James Glen of the Menes in the Liverpool crew list in 1910, and age and birthplace suggest it ought to be, then his previous ship was the Teutonic. Which was then running from Southampton to New York.
So he could have met Sophia in Southampton.
During 1911 the Teutonic was switched to Liverpool - Montreal, and James Glen joined the crew in September!
Earlier that year he was on the Lackawanna, from 4 January to 13 February.
Discharged at Birkenhead??
Next engagement in June (Cedric to New York)
So he ought to have been at home for the 1911 census? As he apparently is, of course.