The ocean if I remember correctly can represent your emotions, so if the theme of the ocean keeps reoccurring then it might be telling you something.
I got to a point a few years ago where I wanted to make a change of myself, and I had these reoccurring dreams of the ocean, and also whales and dolphins. Whales are supposed to represent a re-birth, and in my dreams a lot of the time the ocean was really deep and scary and mysterious. I finally worked out that it meant I was attempting a rebirth for myself and my emotions, but it was going to be very scary for me, and I've never had those dreams since.
I hope that gives you help somewhat.