Mick, I identify with the concept of "ideas for songs".. that's mostly what I have. However yours sounds like a whole song to me! I liked the chord progression, especially in light of the instruments used in the composition. Furthermore, you have a melody that could be hummed and recognized apart from the chords, which is always a good thing.

Speaking of Sunset beach, I'm somewhat familiar with it. We normally vacation on Holden Beach, very near by. I understand that's one of the few places on the east coast where you can watch the sun SET over the water (hence the name)