An Act amending the act of May 28, 1931 (P. L. 202, No. 121), entitled, as amended, "An act providing for the registration of motor boats and the regulation of vessels operated or navigated upon, over or through inland or tidal waters, whether artificial or natural, within the Commonwealth; conferring powers and imposing duties on certain police officers, the Pennsylvania Fish Commission and the Navigation Commission for the Delaware River and its navigable tributaries, including the enforcement of certain existing laws; granting powers and imposing duties upon the Department of Revenue; and prescribing penalties," further providing for the issuance of boat capacity plates; authorizing certain fees, making a repeal and providing for the compilation and release of statistics relating to weight carrying capacity and safe powering of vessels.