I put mine in the back of the boat, mounted with slicone on the floor against the transom beside the plug. I ran the hose up over the transom and secured it with a plastic pvc clamp like the one pictured below. Being that my battery was right there it was easy to intall a switch in the corner brace. If your gonna use silicone to install it, let it dry overnight before you go pulling and tugging on the unit to run the wires and hose. Silicone holds great, and you dont have to drill any holes.
I did mine similiar, just drilled and tapped a peice of 1/4" aluminum and screwed the pump base to it after welding it to the floor (silicone would work as well) I can pull down to around an inch of standing water or even less if I pump as it's going on plane. I'm seriously thinking about a float switch so it's one less thing to juggle while getting the boat underway.
Mine just sits on the floor, not attached to anything. The wires are held close to it, the outlet runs up to a thru-hull on the rear side of the boat. Pretty simple. It was attached to the floor with some caulk by the prior owner, but that came off. By not being attached, I can clean under it. It still sits fairly level, and functions fine.
I have one that the previous owner made to keep rainwater out. The pump and switch is mounted on a 1"X10"x24" that was kept in the back of the boat. It was made so he could take it out when he went out in the boat. The discharge line was just hung over the side. He kept the boat tied up to his dock.
I mounted mine with 3M 5200....I may never get it off if I have to change it. I ran the hose to the side of the boat up at the gunnel so that I can see and hear the water coming out if there is any.
Samething here, going to mount mine with 5200/4200 and then attach the hose to the hook shaped hose from a washing machine drain hose and let it hang/hook over the back of the transom..
Mine is mounted to a rib with two ss screws, It has a auto float switch wired to it. It also is hard wired to a switch on my panel just in case. It is hosed out the side like on a bigger boat. My pump is a attwood 500gph, It will almost keep up with a missing plug when the boat is empty. Just make sure you can reach it, mine tends to suck leaves around it clog it up from time to time.