The “Captains School” short course usually teaches to the test. About the only useful part of the test to a charterer is “The Rules of the Road”.
Sea time : The 360 day’s for an OUPV “aka 6Pack” can be documented in a canoe and also for the Masters 720 days, 50 tons and up if one wants to be creative.
Twice on charter and twice on deliveries I’ve had “Captain certified” crew scare the hell out of me with their lack of knowledge. Maybe they forgot what they learned or answer “C” wasn’t relevant.