That pan is by design supposed to catch the "oily" water to prevent pumping overboard with the bilge pump. Your most likely water source is the shaft seal, which should be repacked and adjusted, or replaced with a dripless seal.
Perfect, thanks. It's good to know not to put a hole in the pan. The drip is definitely coming from the stuffing box. We'll see if I can fix that without hauling the boat.
