The upper drawer is a pull out drawer.
The lower door is a cabinet door.
I don't think you could put the discharge hole above the waterline. The bottom of the sink is only about 4-6 inches above
the resting waterline. When the boat heeled over you would probably get some water gurgling back up the sink.
Here's a picture of the sink unit while I was taking it apart.
I have no idea why I was fairing out the wood under the sink. I must have had some leftover goop.