In order to operate a boat in Oregon, you must carry on board your certificate of number.
16
I am pretty sure that you need a licence to operate a boat. So unless they have a boat licence the answer is no.
16
13
Only with an adult holding a valid boater education card
21
At least 16, to operate a boat you need a valid drivers license.
200 feet
This depends on state or national law. In many places, if you have a valid driver's license you can operate a boat, and generally a boating safety course is so you can operate a boat without a license. In other places, both may be required in order to operate a boat.
16 year old with a boaters education card.
200