The swan does not like the noise and nuisance of the jet ski. Probably, at one time, someone decided to get too close and antagonize the swans with the jet ski. Eventually, something or someone is going to get hurt in this situation. If the male is following the jet ski, then the swan could get hurt if someone started trying to hit him with the vehicle or kick/throw something from the vehicle. If the swan seizes an opportunity to get to a person who has fallen from the vehicle, the person could get seriously hurt. The best thing that can be done in this situatiion is to have the homeowners around the lake discuss the family of swans and impart rules that mandate the jet skis keep a safe distance from the swans. The Regal Swan