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| 20 Electric Bilge Pumps Tested Top performers from Attwood, Lovett, Rule, West Marine and Whale vary considerably by model, but when all is said and done, we like the Whale Supersub, Rule-Mate and Lovett 1200.
This combination is enough to handle the water between weekends—if there’s nothing more serious than a packing gland that drips a drop a minute, a portlight that needs rebedding or rain water. In an emergency, the pump, if adequate to the task, may keep the boat afloat for as long as the battery lasts. Specious, indeed, is the notion that a small boat (15’-30’) can get by with a small bilge pump. A small boat holds far less water and therefore, with the same leak will sink much sooner than a bigger boat. So a small boat needs a big pump—so too does a big boat, maybe even two or three. And the bilge is a great place for redundancy. There are three basic questions about 12-volt bilge pumps: • Do they move as much water as the manufacturers claim? The cost of these pumps when compared to the amount of water they move, is not really an issue, in our opinion. In other words, spend a few extra dollars to get the pump that moves more water. Other questions concern how long they last, the sturdiness of construction, the adequacy of the screen or grill that substitutes (usually poorly) for a good strum box, and how easy they are to clean. To avoid too-frequent cycling, which can be annoying and wastes electricity, automatic pumps are designed to allow bilge water to accumulate before kicking in. Shut-off points are calculated to turn the pump off before it runs out of solid water and starts sounding like schoolchildren finishing their milkshakes. The noise these pumps generate bothers some boaters but others like a little whining so they know it’s working (we do). Boats with bilges that have minimal horizontal dimensions—which means they have narrow and deep bilges—are the most difficult to deal with because the bilge fills quickly, with the pump removing little water in each cycle. This means the pump turns on more frequently. (This occurs most often in boats with internal ballast but with an aft bilge cavity, often forward or under the engine.) This report evaluates all of the above issues except for durability. The short-term warranties (most of them are one-year) should be a tip-off that bilge pumps should be replaced fairly often. How long submersible bilge pumps can survive in the truly scuzzy quarters assigned to them is not only beyond the scope of a bench test, it also would vary greatly with the conditions aboard individual boats. Some boats leak very little and have immaculate bilges. Others may leak considerably and have bilge water containing everything from WD40 to human hair to M&Ms. Bilge pumps get clogged, so ease of cleaning was a critical criteria for this test. The Collection Most are from two manufacturers—Rule and Attwood—who have the most extensive range of submersible pumps. Others are from the respected Irish company Munster Simms (Whale pumps); several old-line firms, Lovett and TAT; and two pumps from West Marine that are made by another old company, Johnson Pumps.
Some come with built-in float switches. We prefer a separate float switch; that way if either it or the pump fails replacementment of the entire unit is not necessary. In the February 1996 issue, we reported on 11 separate switches of four types: pivoting arm, conductivity, air pressure and magnetic reed float. All were cycled 20,000 times. The winner was the Ultra Pumpswitch Sr., now $125, or the junior version, $90. All but one of the pumps were tested head-on. The exception, the TAT, which works on an entirely different principle, is discussed separately in a photo caption on Page 25. The Test The ratings serve only for comparison. When lift is introduced, few pumps—and no centrifugal pumps—will produce their “open flow” ratings. Testing was done at a 5' lift and then compared to the manufacturers’ ratings, which were calculated at lifts of zero, 3.35' and 6’7”. We felt that 3.35’ was too low and 6.7’ was too high. To compare our results with their's, we extrapolated the manufacturers’ ratings to a 5’ lift. We used smooth-bore Shields Series 148 hose of the size specified for each pump. A constant (but adjustable) source of DC power was supplied by a Daiwa PS 120MIIA transformer. Amperage draw was measured with a Radio Shack Auto-Range Digital Multimeter. An attempt to measure noise with a Quest Electronics Model 211A Sound Level Meter proved impractical because the pumps made too little noise when placed under water in a heavy plastic container. Fresh water was used (you'll get lower flow figures with salt water because it is heavier), and while changing pumps, it was siphoned from the calibrated tank back down to the supply tank with a simple arrangement of Whale Quick Connect piping, which included a handy valve to hold the water column in place while changing pumps. The Results However, any of these pumps may give you time to find and fix the problem. Almost all have lead wires that measure 27" (Rule, Whale, West and Lovett) or 32" (Attwood). It would be better if they were longer by several feet so that crimp connections could be made outside the moist environment of the bilge area. The Attwood Guardian 500 has a 42" lead; the West 2200 has a 65" lead.
It further should be noted that Attwood pumps are not equipped with tinned wire. Tinned, fine-stranded copper wire is vastly superior to untinned copper wire because water will migrate through the wire and corrode plain copper wire. Attwood has no plans to use tinned wire because its wires are protected with a silicone caulk, says Attwood designer Bill Mulligan. There was a significant range in the difference between the actual volume of water moved and the manufacturers’ claims. In fact, the spread ran from 216% to 85% while using 13.6V and 148% to 68% at 12.2V. The Lovett, the Whale Supersub 360 and the Whale Supersub 500 were the best three pumps—tested while pumping at a 5' lift against the manufacturers’ claimed volume (zero lift) when operated at 13.6V (as though the batteries were full and the engine was running), When operating at 12.2V, which is far more likely to be the case—especially with an automatic switch on a boat sitting over a weekend—the best tested against the manufacturers’ claims were the same three, but in different order. Other Calculations Theoretically, given the same limited supply of amps, a small pump drawing a small amount of power might be expected to move the same volume of water as a big pump drawing a lot of power. The small pump would just take longer to move the water and exhaust the power supply. The test range was consequential. At 13.6V, it extended from a high of 274 gallons to a low of 112 gallons. At 12.2V, the range was 303 to 123. The top three pumps, working at 13.6V, were the Attwood V1250, the little Attwood 500 and the Rule Model RM 1100 (also known as the Rule-Mate). Working at 12.2V, the above-named top-three pumps again excelled, in a different order. Bottom Line Of the two West Marine pumps, the small one did well, but the large one was a disappointment. If it’s an inexpensive pump you’re after, the West 500 wins Best Buy honors. Lovett’s Model 1200, a very solid, well-executed design, performed very well but only when supplied with 13.6V. When operated with 12.2V, it slipped down in the gallons-per-amp rankings. Still, it pumped more than its rating. The best of the rest? Rule’s Model RM1100 (a.k.a. Rule-Mate) ranked third overall; the Rule Model 27D, very modestly priced, tied for seventh; and the Rule Model 09 (a premium pump; a.k.a. the Rule 5-Year) tied for ninth. The three Whale pumps tested sixth, seventh and ninth, the latter two in ties with the above-named Rule pumps. Although mediocre performers in the volume-per-amp category, Whale is distinguished for pumping very close to what it claims. In addition, these new pumps are compact, easy to install and appear to be made in the Whale tradition. They’re a mite pricey. Our favorites? • For a small pump: the Whale Supersub, preferably the manual version with a separate switch.
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