At Rockaway Reef, Krainov drops a buoy where the fishfinder jags upward from the rocks. When he strays on his dives, he’ll be able to reorient himself after surfacing by using the buoy. It’s low tide, and there’s hardly any current, which is prime time for diving. Here, the shallowest point is 25 feet, and the ocean floor is 35 feet deep. Yesterday, the manmade reef, composed of steel buoys, concrete slabs, decking, and other industrial rubble, was what Krainov called a “parking lot of boats.” Today, there are only a few boats nearby.