It shall be unlawful for anyone to operate a motorboat on Louther’s Lake near the Town of Mechanicsville in Darlington County when the boat has onboard a motor which has a manufacturer’s advertised horsepower greater than ten. It shall be the responsibility of the department to post and maintain at each major landing on Louther’s Lake a three foot by four foot sign, visible to users of the landings, on which the foregoing prohibition shall be plainly lettered. Anyone operating a boat in violation of the provisions of this section shall be fined not less than fifty dollars nor more than one hundred dollars, or be imprisoned for not more than thirty days.