As Bumpyroad mentioned, many states are now requiring an endorsement to operate watercraft and an age limit similar to drivers licenses. Sure, you can fail and retake the test but you have to watch the videos first to know what answers they are looking for. The point is that at a minimum you are seeing the proper way to operate your equipment, rather than driving off the lot with little or no instruction from some salesman who is certainly not going to say you are not experienced enough to take delivery. His total focus is to get rid of you so he will be available for a new customer.
And the throwable for a single occupant of a boat is to rescue someone from another boat you may find in the water.
