First was a small unit, handle the occasional dribble. Second was a medium sized pump, handle a small leak. Third was a giant sized thing, about the size of a gallon paint can - the pump of last resort. Switches were nicely staggered so they would come on in sequence. Bad news is a) undersize wires, wouldn't handle the pump current, and b) undersize breaker, the single breaker was sized for the big pump ONLY! Great, the big pump comes on and 3 sec later they ALL shut off.
Oh yeah, sold the boat...