Section 21. No person under 18 years of age shall operate a recreation vehicle unless he has successfully completed a recreation vehicle safety and responsibility course approved by the director of environmental law enforcement. The director may exempt a participant of a sanctioned race, rally or event who is not a resident of the commonwealth from the requirements of this section. Such course shall include, but shall not be limited to, notification of the potential criminal penalties and forfeiture process for certain violations of law relative to the safe operation of recreation vehicles. A parent or legal guardian of an operator of a recreation vehicle under 16 years of age shall participate in at least 1 session of the recreation vehicle safety and responsibility course or as required by the director. Proof of the successful completion of the course shall be carried on the person of the operator while operating a recreation vehicle. Proof of an operator's successful completion of another state's equivalent recreation vehicle safety and responsibility course, as determined by the director, shall be valid in the commonwealth.