A person in charge of a boat or vessel who has no experience other than the training they received to fill the position they are in. Straight from the farm to the helm. Inexperienced boater. One who took the orientation course from the dealer and headed for the bay. Many young Navy and Coast Guard coxswains or deck officers fit this description until they get some miles under their keel.
Keep your wits about you, there's a lot of Nebraska Sailors on the water today.