It is unlawful for any person operating any motorboat to tow any canoe while such canoe is occupied by any person, and it is unlawful for any person operating or occupying any canoe, sailboat, motorboat, or rowboat to make fast to any log raft being towed through the harbor.  No person operating any canoe, rowboat, or motorboat shall pass between the stern of any towboat and the raft in tow thereof.