Devil's advocating: I did exactly this several times in my sailing career. Military vessels are regulated by the same international laws and rules as all other sea navigation subjects.

Fellow sailor crossed the course of Turkish submarine while under sail (meaning he had a right of passage). It was in Turkey's waters (!) about 10 years ago. Instead of changing course they made an emergency dive exercise.

> Instead of changing course they made an emergency five exercise.

It’s gotta be fun to have three dimensions of freedom available when making course changes.

But man, I’d freak out if I were on the sailboat watching that happen!

Me too! But he is a racer and was ready to do a quick tack just in case.

Unless you’re a lighthouse

Those are unlikely to be in international waters. I do know the old joke you’re referring to, though!

Thinking of xkcd1053....

https://www.snopes.com/fact-check/the-obstinate-lighthouse/

Not just a warship. Regular boats are also fed up with piracy and have some pretty nasty countermeasures.

Greenpeace used a non-lethal attack involving stink bombs from hell... glass bottles filled with some kind of oily sulfurous compound that got on everything. I wonder if anyone in commercial shipping does that. Definitely not something you would want to test.

If it's painted grey, get out of the way!