Not only should you have a second bilge pump but you should consider a bilge pump a bit bigger than what is typically installed. Spray or rain - anything can keep up with that. The bigger concern is a wave over the back. This won't happen under most sensible situations - but sensible situations are not what get boaters in trouble. The most common ways to get a wave over the back are - backing down on a fish, shrimp or crab pot and anchoring from the stern. The last one's just plain dumb, the first one is sometimes necessary. One little wave can easily bring in 10 or 20 gallons of water (80-160 lbs), a bigger one can (of course) bring in more. An 1100 gallon per hour pump removes about 18 gallons/minute, waves are typically spaced <10 sec apart. Just 3 gallons over the stern per every 10 sec wave is 18 gallons per minute - the capacity of the typical pump. Once you get a good bit of water in the cockpit, the stern sits lower and the waves come over more easily. It doesn't take very long for a boat in this situation to fill the cockpit. The floundering boat then capsizes. Add in a second pump at say 2000gph, and now you've got a total of 3100gph which gives you close to 50 gallon/minute of capacity.
Other considerations -
* One of the most important things to do if a wave comes over the back is to get on the throttle such that you can prevent additional waves from coming over. Those who manage to flounder and capsize their boats often don't realize how much potential trouble they're in until it's too late. With waves 10 sec apart (a relatively long period in the NW), it only takes a minute to get hit by six waves. If you're worrying about gettting your fishing tackle stowed up your downriggers up prior to getting on the throttle, it may be too late. One should also infer that it's a good idea to have the engines running when ever one's in large waves. This may sound obvious, but the
people that were rescued last year by our own Starcraft Tom and Sark made the mistake of shutting down the engines in following seas (plus many, many more mistakes) and didn't recognize the seriousness of the problem early. Their self bailing cockpit (in a Trophy) didn't help in this situation.
* Check the bilge pumps prior to each outing. Clean the screens - especially if you bring pets on board. With out dog, it seems like every hair that comes off him in the boat, finds it's way to the bilge pump. If you leave your boat outside and uncovered, leaves and pine needles find their way there too.
* Where are your batteries? How much water has to be in the cockpit before your electric bilge pumps won't work? If the batteries are on the floor and the terminal exposed, it doesn't take too much water to short things out (especially in salt water).
* A manually operated bilge pump is not only a good idea, it's required in some places (like Canadian waters).
* Always size the hose and through hulls to the manufacturer's specs, don't use more hose than is necessary and limit the rise on the through hull to what is needed. Small hoses, long hoses, small through hulls and a having to raise the water very far all reduce the pumping capacity.
