Do all big vessels take a pilot on board?

Today, a listener question about marine pilots: which ships take them and which don't?

In the majority of cases, it's a matter of the law. And we certainly see a lot of local domestic vessels, like tugs and excursion vessels, and US-flagged river cruise ships, that don't take pilots. Their captains know the river well.

But almost all large visiting vessels operating in land waterways, worldwide, use the services of marine pilots, for safety reasons.