Ruth Wilson, daughter of a wealthy landowner, receives a visit from her country sweetheart, Joe Merriam. who is a motorboat enthusiast. Unknown to anyone but her brother Frank, Ruth is an expert at fixing auto and motorboat engines as the estate is on the bay and Ruth has the use of two launches. With Joe she goes for a boat ride but the engine breaks down and he is unable to fix it, and afraid that it would lower his opinion of her if she should repair the engine, she lets him call another boat to tow them back to the wharf. Merriam, while in love with Ruth, cannot bring himself to propose, fearing that she would be too ornamental for a farmer's wife, and half of his visit passes while he attempts to make up his mind. Finally, the last day of his visit arrives and he is still undecided. At the request of Ruth's father she and Joe take the launch across the bay to bring back the money for the servants' pay roll. While Joe is at the bank, Ruth remains at the town wharf and is accosted by a couple of toughs who demand the expensive rings she is wearing. At Joe's return they slink off, but watching the launch on its return set it adrift with the engine dead. In a rowboat they follow to board the launch and secure the money and Ruth's jewelry. Joe, unable to repair the engine, gives battle to the toughs to prevent them from gaining the launch but he is being forced down when Ruth, realizing their desperate plight, begins to work on the engine. Just as the toughs are about to overcome Joe, she has the engine repaired and starts the launch, leaving the toughs far behind. Joe, seeing her with her hands and face covered with grease from the engine, realizes that he has misjudged her, and proposes on the spot. At her acceptance he takes her in his arms, grease and all.