Witz is right
Of course that could also apply to the drain for the galley sink and the icebox/shower.
I for one don't know why Catalina as they always strive for efficiency and economy don't do away with the paddle and the through hull depth sounder. You can get the hockey puck depth sounder that shoots through the hull just fine and you can get speed off of the GPS. There are some advantages to the paddle, but I suspect most of us have no clue how to interpret them. That way you would have two fewer hull penetrations.
Of course that could also apply to the drain for the galley sink and the icebox/shower.
