Obvious, well yes, but...
I've had a beard almost since I need to shave and didn't, but the moniker didn't come until quite a bit later. I was a scout leader at a Sea Scout group and one of the boys called be Captain Beardy. It sort of stuck. But one of our friends is a master merchant mariner, at the time sailing with the Stenna as a first officer. the fact that she had her Masters ticket and wasn't a captain was something of a sore point with her1. The fact that I did not have a Masters ticket and was also not a captain was not really an issue, but she was damned if she was going to call me Captain Beardy, so I became just Beardy.
1. She did sail as a captain for Stenna, the first female to do so, but only as a relief. She's since left them and now works as a Pilot out of Felixstowe and Harwich.