A skilled crewman

 is a Sunless Sea Random Event.

Trigger conditions
 is triggered at zee if you have the following:  A New Face ≥ 1 and ≤ 75 The Gods of the Zee: Stone, Storm and Salt ≥ 1 

Event description
This is the zailor who came begging to you for a berth. He's done good work, this one. But he's keeping a little shrine to the Salt, the nameless god of the horizon, at the back of the hold.