Sorry for the title, but I didn't know what else to call it. I guess I have what I think is a really stupid question but since I don't know the answer, I have to ask it. OK, look at the picture below.
This is an example of what I would call a portable ballast pump. Now the "stupid" question.
Since these pumps (rule, Atwood, etc.) are not reversible & they don't appear to be set up to swap the hose from the "in" side to the "out" side, are you supposed to lean over the side of your boat & only submerge the 2" long nipple on the "in" side to pump the water or are these pumps designed so you can submerge the entire pump in the water? Does this make any sense?