When two or more vessels are involved in a collision, accident or other casualty, the operator of each, so far as he can do so without danger to his vessel or to its crew or passengers, shall render to the other vessel, its operator, crew and passengers such assistance as may be practicable and necessary to save them from danger caused by such collision and he shall stay by such other vessel until he has ascertained that there is no need of further assistance. Each such operator shall also give to the operator of the other vessel his name, address and the identification number, if any, of his vessel. Failure of an operator to comply with the requirements of this section, unless reasonable cause for such failure is shown, shall be prima facie evidence that the collision was caused by his wrongful act, neglect or default.