Two of the three raw water inlets for our A C pumps are outboard, P & S, 2 feet inside the chines, mid ship. Problem is, sometimes in slop or at speed, the pumps pick up air and loose prime while under way. My third A C pick up is way down close to the port keel mid ship. It services the forward cabins. Rarely used while under way. Always figure it wont pick up mud or silt when I mess up sense mostly never used while under way. I've often thought the water would be cooler, the deeper and away from the sun. I'm planning on updating the A C pumps and plumbing to them. The question; Is the water really cooler 2 feet deeper? Any advice welcome?