Twilight and the Bay Cave

I am in the car with a young man who I think is my younger brother. He kind of looks like me, and has the same hair color and eyes but is smaller. We are driving in San Francisco. The sky is really remarkable - my favorite color of twilight sky that a sort of blue-green. I kind of marvel at the sky for a little while. I notice the outline of the transamerica pyramid in SF. Then I am on a bridge. My brother is still in the car. The bridge suddenly stops at about mid-way and the car falls into the Bay water.

The next thing I know I am on some sort of beach. It is still that same twilight color. There is a cabana with a woman working there and a few other people. Someone asks my brother and I if we'd like to take a look for my car under the water. I say 'sure' and now I am at the edge of the ocean. This next part is weird: The water is being propped up by wooden planking - like its a flat surface that can be held up. The inside of looks like a cave.

My brother runs right inside to look for the car but I hang behind and check the wooden support system and the ceiling to make sure its safe. There is a guide with a light. We go through two different cave chambers but when we get to the third chamber where my car is supposed to be something makes me afraid and I tell my brother to get out of there. We both start to run.