Book about young girl and her big scary man friend

I read this book for class in the sixth grade I believe. The story is hard to recall but I remember the main character being a young child, a girl I believe. And she befriends a large and frightening man who wears a rattlesnake rattler around his neck. I recall him being described as big and imposing, there was an air of danger around him, I think the girl thought he was a criminal of some kind and I believe he was. I want to say he wore camo shorts and no shirt and the necklace and had a mysterious and salty kind of personality but protected the girl. I want to say it was also related to the beach in some way? Please help this is torturing me lmao