Thanks Andrea. I've agonised over this, and I'm sure you're right - sailors weren't called Jack Tars for nothing!
I had intended to 'weather' his bandanna and cut-down trackie bottoms - but I've simply bottled it. I'm putting him on shore-leave, so his clothes may be threadbare, but he's scrubbed-up nicely!
For me, he smells of tobacco, wet leather, clean sweat - and maybe a dab of Chanel No.5 he took a fancy to in a lady's chamber while out pillaging.
If that's not credible, he'll simply have to be an extra in a production of 'The Pirates of Penzance'.