Bilge pump size

[JohnD]

Tomorrow's project on my Triton refurbishing is replacing the old bilge pump. I was wondering how big of a pump other people have installed, their reasoning behind it, and what they plan on changing next time. Any suggestions?

[Rachel]

John,

What do you have for a set up now? I ask because I tend to think about bilge pumps a bit like ground tackle - as a system. Are you replacing a manual or electric? What is the total inventory of pumps aboard now? How are they set up? Does your boat live connected to shorepower, on a mooring, etc.?

Not that there is any one right answer, but it's easier to opine with a bit more of an idea of what you have/want.

Rachel

[JohnD]

As of right now I have nothing. There was an automatic pump with a built in float, but it got trashed while trying to remove it to clean it up. So right now my total count is....0. Nice huh?

The boat is in a slip at a marina and will be until at least this summer. Constantly hooked up to shore power, so running a battery dead isn't going to be an issue.

I am planning on putting a manual pump in as backup before sailing, but for now it will have to live with just the one.

I was at the store today and couldn't decide how big to go. 500 GPH? 750? 1000? Too many choices. If it helps, I will primarily just be doing day trips in the Chesapeake for the next couple of years (at least). This makes me think I don't need to go too big.

[Duncan]

500 GPH? 750? 1000?

That depends on how high you have to lift the water.
One good setup is to have a small pump deep in the bilge, and a large one higher up. The small one takes care of drips and small seeps, and capacity doesn't matter so much. The larger one, higher up, is the "save your boat" pump, and its' capacity is not so affected by "lift" because it doesn't have to lift the water so far.

[Rachel]

Another advantage to a smaller, "drying" pump is that you can use small diameter hose, such as 3/4" and there is less water to flow back into the bilge. OTOH, I guess it depends on how many pumps you plan to have in a Triton, and where you can put them all.

One note is that I can't stand the "automatic" bilge pumps. By that I mean that there is a type that "automatically" cycle on and off every "x" minutes, whether they need it or not. That would drive me nuts. I spent a few days on a boat where the bilge was so shallow that was all they could fit, and even the owner told me to just switch off the pump at night. With a deep bilge I wouldn't want to put up with that. I think these usually have the switch and pump together as a unit.

Although with shore power you can theoretically power any pump, I think I would still prefer a setup that could reasonably be powered by the boat's own systems (and of course with the boat having no pump-requiring leaks, good hoses and clamps, etc.). I could just imagine that at the same time the marina's power went out (storm or whatever) is when I would need the pump(s). I have been at marinas where there are boats whose owners rely on shore power and large pumps to keep their boats afloat, and it is nerve-wracking when the power goes out (or may go out).

I can't actually remember what size pump I put on my A-30 (now that sounds dumb), but basically it was a reasonably small sized electric pump and float switch, both mounted on an L-shaped "leg/foot" that was suspended into the bilge so that I could pull it up from time to time. The "big" pump capacity was a manual pump. So my set-up would not have "saved" the boat from much without someone being aboard to take things in hand, but was fine for nuisance water and for something that could be caught and taken care of (but I tried to eliminate those "somethings" before-hand).

[JohnD]

Thank you for your explanations. I'm glad you mentioned the automatic pump. I was wondering why I shouldn't use one of those rather than a regular one with a float switch wired in.

[sscoll]

For what its worth, on EC Triton 532 I use a 1000g/h on a float switch led through the transom as well as a hand pumped diaphragm gusher led to a separate transom discharge. Additionally I carry a spare 500g/h in a box and a bucket. I don't use shore power. I haven't gone to the lengths James has, but if I were to circumnavigate even once I probably would. Keeping the water on the outside is worth paying attention to. Our water is unfortunately quite hard this time of year.
Steve

[Tim]

Remember that if you need shore power to ensure your bilge pump doesn't run down the batteries, then way too much water is coming into the boat from somewhere. Find out where, and stop it.

In my shallow-bilge Triton EC #381, I have a 1500 GPH Rule centrifugal pump with "super" float switch, plus a manual diaphragm pump (Henderson MK IV), both of which I installed new in 2001.

Over the years and in a variety of situations, I have tried a number of "sampling" self-contained auto pumps (the ones Rachel mentioned), plus pumps with "computerized" auto switches (some self-contained, others separate), and have been disappointed over and over. I much prefer old-fashioned float switches, whatever sort of pump they're attached to.

My preferred installation for a routine dewatering pump is to use a remotely-located electric diaphragm pump with suction hose (and auto switch) led to the deepest part of the bilge sump. These pumps are more reliable to begin with, and the ability to locate them far away from the dampness of the bilge encourages their longevity. They also cost a lot more, which is why you don't see more of these installations. This is how I will do all future installations on my own boats, however,

Whatever the installation, one should never expect any automatic bilge pump to keep one's boat afloat in one's absence. If a boat's buoyancy is that tenuous, then there are much larger problems to be dealt with. Thinking like this helps keep proper perspective on bilge pump installations and forces one to consider the more important issues at hand, like keeping the water out to begin with.

[Quetzalsailor]

I have a nice new Gusher, plastic, manual pump, thanks to internal corrosion of the previous new-looking aluminum Gusher. But for everyday comfort, I have a Rule 2000 enclosed automatic in our 38 footer. It has some sort of switch within the case that senses depth of water by magic. That range of depth is, of course, within the height of the case; in practice, it's about 4 inches. It replaces an earlier Rule 2000 automatic of the sort that tests for water by sensing load on the impeller; it had a timer which ran the pump every few minutes. In practice, it would try to pump out the water that had dribbled back from the one-way valve, so would actually run for a few extra seconds at each trial. Both were supplied with less wire than the easy depth of available water in the bilge, thus are susceptible to failed, corroded splices. Of course, if they're working, water would never be that deep. Drains from the forward bilge, the shower, and the refrigerator are carefully positioned to wet the wires, too.

Pumps fail for a variety of reasons: electronic widgetry, occlusion of the impeller, power supply - battery or leads, dirt and growth on the float switch, the float switch no longer lighter than water, failure of the motor itself, corrosion. I have, over the years, enjoyed them all, either in my basement or my bilge. Anything you can do to reduce the likelihood of any of these failures, particularly ease of access for maintenance, and keeping the bilge clean, is worth the bother.

All this worry about size is really not important. Install the largest that's reasonable in terms of battery and electrical system capacity and suitable for the drain size overboard. No pump that meets the above criteria will be big enough to cope with any catastrophic failure, even a small through hull, a shaft bellows or hose.