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For what it’s worth, I’m several projects ahead of my blog updates. I just haven’t had as much time to blog lately as I would like. Let’s hope that changes in the near future. (Also, kicking myself right now for not naming this blog series Ship’s Log!)
The bilge of my boat is to scale for a ‘pocket cruiser.’ It is considerably shallow (between 1-1.5 in. deep), and isn’t much larger than the sole of the cabin (roughly 8 ft. long by 4 ft. wide). It’s a small boat and like many smaller sailing dinghies it isn’t usually outfitted with a pump. It acts like a basin for the occasional topside leak, rain ingress or dripping-wet swimmer. Sailors with this type of bilge will typically empty it with a sponge or small siphon once back on land or at the dock.
Yet there are a few reasons why I need to install a bilge pump. First, there is a small hull leak around the keel trunk and on my shakedown cruise last October it was enough to fill the bilge in an hour’s time. (Apprently she was waterborne for most of 2016 with that leak.) Even though I intend to fix this leak completely, the ability to evacuate water from a 50-year-old boat cannot be undervalued. Also, to find and fix the leak, I’m going to need to fill up the inside of the boat with water; eventually all that water will have to be pumped out.
Lastly, my state is quite strict about invasive species and all bilges must by dry before a boat can be launched in a new lake. Several law enforcement agencies inspect and regulate this heavily!
Ideally my boat will have two bilge pumps for redundancy’s sake, but for now one will have to do. I elected a manual design because I didn’t want to have another appliance drawing electricity and also because most electric pumps are submersible, and none (or quite few) would fit the very shallow dimensions of my bilge area.
The Boat Owner’s Association of the United States recommends a pump output of 450-700 gallons per hour for a 20 ft. boat, and using this as my guidelines I bought the Whale Compac 50 (for myself, for Christmas, back in 2016).
Installation started by drilling a 3-3/8 in. hole into the storage locker underneath the port side quarter berth. I selected this location because it provided ample space to stroke the pump and also observe the bilge level from the cabin. The bilge gasket and deckplate installs on the outside of the locker and a removable handle ensures a clean aesthetic when the deckplate is closed. Installing the pump in the locker was painful because there are four screws the needed to be blind-threaded from the deckplate into the pump. After two hours and some blood loss I eventually got it aligned and tightened.
Bilge exhaust plumbing requires a mechanism known as a vented loop. This mechanism prevents water from siphoning back into the boat should the bilge exhaust ever find itself submerged. This is perhaps a little bit overengineered because my bilge exhaust is above the waterline and the manual pump should prevent water from siphoning all to way back into the bilge (which should only potentially happen on trailer launches and haul-outs). On my Matilda, the vented loop is positioned high along the inside transom wall, not far from the repair shown in Fiberglass-By-Numbers. It was screwed into a painted piece of wood that is epoxied to the fiberglass.
The 1 in. diameter pump intake hose runs underneath the boat’s kitchenette(-ette?). The sink currently drains right into the bilge so I ran the hose alongside that drain line, but continued the hose underneath the cabin sole. The end of the intake hose has a plastic screw-in strainer. The pump output, also 1 in., runs along the locker area before it has to extend underneath the cockpit floor so it can meet the vented loop. The loop is connected to a 90° stainless steel through-hull located on the upper starboard side of the transom. The hose connections are held tight by hose clamps, while the through-hull was secured with some 3M 5200 marine sealant and a plastic nut.
 
Today, I’m happy to report that my Matilda can expel water whenever she needs to.
Other completed tasks:
- Installed six vents around the cabin and cockpit to increase airflow in storage lockers
- Replaced all hardware on rudder assembly
- Installed new tiller
- Painted bilge cover boards
 
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Re: The Sailboat Diaries: Building a Bilge
