The video shows a marlin fish swimming in the ocean. The fish is dark in color with a long bill and a pointed snout. It is swimming near the surface of the water, which is a deep blue color. The fish is moving its body in a smooth, gliding motion. The video is taken from the perspective of someone on a boat, as evidenced by the edge of the boat visible in the frame. The boat appears to be stationary, and there are no other fish or objects in the water around the marlin.