calling all dream interpreters

I keep having re-occurring dreams about water. Last night, I dreamt my grandparents bought a houseboat in Santa Monica. Right outside the main door of the house were a bunch of rocks, like you find at beaches. If you left the front door open too long, huge crabs would bombard the living room. From the balcony of the house, you could see the waves crashing way out into the ocean, instead of on the shore. The water was beautiful, but I was afraid of it.

A few weeks ago, I dreamt I was in the Caribbean with a study group from college. I think we were studying computers or something weird like that, that I would never study. On the beach there was a shack, used as a control room where an entire wall of computers were set up to monitor something in a parallel universe. I was the only one who went out onto the beach. The sun was shining, there was a cool breeze, and the white sand was warm. I was alone, and the water looked very inviting. It was clear blue and I could see to the bottom. There were no fish, and no seaweed. Just perfect water, and perfect sand. The ocean was calm and relaxing, and reassuring. It was warm, but not hot. I laid on my back so that my ears were underwater and I was floating. I could see myself from up above, and I looked serene.

Just then, I saw a dorsal fin swimming towards me. I became very wary, but not frightened yet. It got closer, and it wasn't slowing down. I swam back a little, to keep my distance. I knew in the back of my mind what the animal probably was, although Icouldn't actually see what was underneath the fin. It was starting to follow me. It got close enough for me to touch it, and I became a little scared. I didn't want to acknowledge that it was a shark, because then it would manifest itself. I told myself it was a dolphin, and as long as I thought it, I would only see the fin.

When I woke up and thought about my dream, I realized it was a shark I saw in the water, I just didn't allow myself to see it. Dolphins don't swim in shallow water like that.

Ever since I was a child, I've had nightmares of Tidal Waves. I've never actually been overcome by them in my dream, I've always just barely been able to out run it. I wonder what all this water means, if anything. Sometimes it's bright blue, other times it's murky. I usually wake up afraid. Does this mean anything?