What is required to charter a bareboat?
As far as I know there is no certification which is universally accepted like a driver’s license. Basically, they have to feel confident that with your experience, you can be trusted with a very expensive boat. Most chartering companies require a sailing resume to show your experience. Actual requirements seem to vary, but mostly they would like to see at least experience crewing on a similar sized boat for a similar period of time. They may require that you go through a test sail with one of their captains to demonstrate basic proficiencies. Certification from a recognized agency such as US Boat or ASA is a plus but rarely completely sufficient.