The provisions of this chapter shall not apply to docking facilities open to the general public or to persons utilizing privately owned docking facilities in an emergency situation, or to persons having permission, express or implied, to use such facilities from the owner thereof, or to any person, association or corporation, and the agents and servants thereof, in the performance of duties arising out of the usual conduct of business or arising out of the terms of a State or Federal charter, license or franchise, and regulations thereunder.