Did he speak with a Scottish accent and appear like he was from the future?
As an old sailor that’s heard more than his share of “sea stories” that usually start in the local CPO club bar that begin with the preamble. “this is no chit”, I suspect this might be the origins of the transparent aluminum. Tales such as this along with the Golden Rivet, Sea Bat, Mail Buoy look out, etc. come to light during many hours of boredom and gullible newbies.