Carrying around a wired spare is for the most part, completely pointless, yes you can replace that burnt out auto on the fly, but what are you going to do if your batteries give up the ghost? Rub the wires together?
Same thing you're going to do when the batteries give up and you actually have dual pumps - not much you can do except watch her disappear...
My bilge is to small to fit another pump with the live well pumps and existing (way oversized) bilge pump. I can clip on the alligator clips and toss the extra pump in the hole - doubles my pumping capacity while I head for the beach. I agree - avoiding the crisis is always better than being prepared to react to it. Doubles as a washdown when the bluefish puke all over the deck too...
