I was just pottering around Townhouse when I came across your synopsis. I have not much to add to the excellent comments already made, and I think Rick's example above shows the right tone & style for a synopsis. This tone (tight summary) would be more interesting for me and show me straight away what the story is about, without any surplus info. In the end, a synopsis is a summary of a story, so I agree with others about going straight to the inciting incident: the shark attack.
Another thing I noticed is that this synopsis starts with more on Josh than Mia. We get to know a lot about him before learning about her. It's almost as if he is the MC. No problem, but if you are writing women's fiction, you must have a female heroine as MC. On that note, you may need to show / present Mia as the center of the story.