Splets,
Some owners are under the thinking of, "well I have a smaller boat & bilge, I can go with a smaller pump."
This is wrong, the smaller the bilge the larger the pump must be. A larger size bilge can hold more water, not so for a small bilge. And, you will never achieve the rated GPM/GPH, when you add head to the equation (vertical rise of the discharge hose). Your pumping capability will be less. With a small bilge, you have to move more water out in a short time if an accident is sending alot of water to the bilge. Keep in mind your engine area is also part of the bilge.
I use the Rule 5000 & it's adequate for the small bilges we have. I am not a lover of internal floats, as I've had two in the past & had problems. It's alot easier/cheaper to change out a separate float switch. Float switches seem to have a shorter lifespan than the pumps.
In addition, keep all you wiring connections high & dry. I run my wiring to a terminal block on the inside of my engine compartment. Then from the block to my panel. This way, you only have to add terminal connecters for changeouts.
CR