I never thought of that, but I remember that more than once in Agatha Christie's mysteries, she mentioned it as a known fact that tough old career soldiers (who had presumably been in many difficult and dangerous situations in far-flung corners of the empire) would be the first to fall for get-rich-quick investment schemes like gold mines in Siberia, which would seem very suspicious to most people. Perhaps there *was* a common stereotype of the absent-minded or naive-on-land sailor!