Mike and the Mermaid

I saw this movie over 25 years ago. I vaguely remember a young man on a beach watching as a girl (mermaid) swims off into the ocean, possibly in the company of a sea turtle. I also have a memory of a boat scene, where the mermaid is wounded, with a fishing arrow sticking out of her back or tail. I cannot recall what the actors looked like, but as an adolescent, I definitely had an emotional reaction to the film. To this day, I have an unexplained feeling of regret or a "longing" towards the mermaid. This may have been because the end left you hanging, or she dies or something.

If anyone has a copy of this film, or know where to get one, please email me! Thanks, Dan