I'm interpreting it as there is a point in the meatspace of your brain that is like a sailboat on a stormy sea. The Water is one level, the air is another, and

I'm interpreting it as there is a point in the meatspace of your brain that is like a sailboat on a stormy sea. The Water is one level, the air is another, and your consciousness is the sailboat that glides around where the two meet.