SOTL

They very rarely appear. It's just completely random if they will show up or not. Your best bet is to play a few games that start in 1680. I've had them show up there more often.

Welcome to my world-where everything's made up and the points don't matter.

Spanish countries don't spawn ships of the line.

To get them to appear you mercilessly attack a countries Ships not town and eventually they will bring out the ships of the line to try and sink you.

So just keep attacking one nation’s ships.

I finished the whole game without seing a SOTL. Then, a few months ago, I started playing it again. After 2 days, I had EIGHT Ship of the Line's. I just ran into them wherever I went, but most of them I think were heading to either Gibraltar or... That rich freanch city just south of Fourt Lauredale. But I had caused mad ruckus around the place, so maybe they felt like they needed some SOTLs.

Good luck

Ive averaged a Ship of the Line every game by constantly attacking English shipping. The English to my knowledge, are the only ones who can field a Ship of the Line. Ive tried the same tactics, on all difficulties, and have arrived at that conclusion. Its a very nice warship but its unmaneuverable against smaller ships, it will make small scale battles difficult. The positive thing is, one good broadside will completely sink a trade ship or a small ship if hit on thier broadside.