You have to have it if your boats motor is over 10 hp, or a sailboat over 14 feet or are on a wave runner.
No not everyone is required to have the course. Old farts like myself born in 1958 are not required to have the certification.
By the letter of the law, the way this is written both conditions must be met to require an operator to take the certification. Not even technically, if you are 19 or older you do not need to take the class. The word
'AND' is an operative that requires all conditions to be true. The intent of this reg on the other hand is I believe to have all operators born after the magical date to have the certification class under their belt. The part about being under 18 is no longer needed.
I could be wrong and the state is only concerned about those under 18, but I seriously doubt it. That would be too easy of a read. Besides if that was the only issue they were interested in, the magical date would not be needed.
I have family members that were born after the magical date and are over 18. I required them to take the certification for one reason. The patrol that writes the citation is not going to be worried about incorrect grammar. To get it cleared up will take additional time and the inconvenience of a court date. That just isn't worth it for a 'sleeper' certification class.