Shipless hammer captain?

I noticed that according to the rules a Hammer Caption who is not a Hammer Lord cannot purchase a hammer craft, yet the hammer captain in the back of the book has one. I assume this mean that if a hammer captain is in active service, the GM is supposed to assign him a ship… otherwise it seems counterintuitive that I cannot make a lord-pilot hammer or hammer captain with an actual ship.

You captain a ship in the service of your Hammer Lord.

Yeah, but how is that handled mechanically?

Do I need to buy a relationship with my lord and then he’ll grant it to me? Do I get it through the affiliation?

Either or. Both have implications.

The real mechanism there is the GM!