{"product_id":"rule-500-gph-standard-bilge-pump-12v-25da","title":"Rule 500 GPH Standard Bilge Pump 12V (25DA)","description":"\u003cp class=\"nvn-hero\"\u003eThe Rule 25DA is the 500 GPH, 12-volt submersible bilge pump that keeps small boats dry without drama. Ignition protected, built around a high-efficiency low-amp motor, and now engineered to hit full flow at real onboard voltage instead of a bench-perfect 13.6V. Wire it to a panel switch or a float switch and forget about it.\u003c\/p\u003e\n\n\u003cdiv class=\"nvn-description\"\u003e\n\u003cp\u003eEvery boat needs a bilge pump that just works, and the Rule 500 GPH Standard is the one we reach for on smaller hulls. It's a compact 12-volt submersible built for the water that always finds its way in, whether that's rain, spray over the transom, packing gland weep, or the little bit that comes aboard every time you launch. Rule has been making these round submersible pumps for decades, and the current 25DA is the next-generation version of a design that's lived in more bilges than we can count.\u003c\/p\u003e\n\u003cp\u003eHere's what actually changed in this generation, and why it matters. Older bilge pumps quoted their gallons-per-hour at 13.6 volts, which is the number you see on a fully charged system with the engine running. Out on the water your battery is rarely sitting that high. Rule re-rated this pump to deliver its 500 GPH flow at a true 12 volts, so the number on the box is closer to the flow you'll really get when you need it. That's the kind of honest engineering we like to see.\u003c\/p\u003e\n\u003cp\u003eThe 25DA is a non-automatic pump. That means it doesn't have a built-in sensor, so it runs when you tell it to run and stops when you cut power. You've got two ways to control it. Wire it to a panel switch at the helm and flip it on when you see water, or wire it through a Rule float switch so it kicks on by itself as the bilge fills. Most boaters run both, a float switch for hands-off protection and a manual override at the dash for when you want to pump the last inch out before you pull the plug. If you want a pump that senses water on its own with no float switch, look at the automatic version instead. This one is the simple, bulletproof standard model.\u003c\/p\u003e\n\u003cp\u003eInside, the motor is a high-efficiency, low-amp design spinning a stainless-steel shaft, so it sips current and shrugs off the corrosive life in a bilge. Rule built in a real thermal cell too, a cutoff that shuts the motor down if it runs dry and gets too hot, which protects both the pump and the boat from a run-on situation. There's also true electromagnetic suppression built in, so the motor won't put noise into your VHF or fishfinder while it's running. Little details, but they're the difference between a pump you trust and one you replace every season.\u003c\/p\u003e\n\u003cp\u003eOne clever touch worth knowing about is the anti-airlock design. Under each strainer tab there's a small vent hole that lets any air trapped in the pump housing escape, so the impeller doesn't spin against a pocket of air and move nothing. Airlocking is a classic bilge-pump failure, the pump hums but the water level never drops, and Rule engineered it out of this housing. The pump also includes a backflow preventer so water in the discharge hose doesn't drain back down into the bilge every time the pump shuts off.\u003c\/p\u003e\n\u003cp\u003eInstall is straightforward. The pump sits low in the bilge, ideally on the lowest dry-ish spot so it can pick up water but isn't buried in the muck that clogs an impeller. The discharge takes standard 3\/4-inch hose to a through-hull fitting above the waterline. Run the hose up in a smooth loop and double-clamp it at the pump, because a single clamp that backs off is how you get a slow leak nobody notices. For the wiring, use tinned marine-grade wire and proper crimp connectors. Untinned automotive wire corrodes fast down there and a corroded connection means the pump won't run on the day you actually need it. Fuse the positive lead per Rule's rating and you're set.\u003c\/p\u003e\n\u003cp\u003eWho's this for? Tenders, jon boats, center consoles under about 20 feet, small sailboats, and as a secondary pump on a bigger boat. It's rated for 500 GPH at zero head, and like every centrifugal bilge pump the real-world flow drops as it has to lift water higher, so size it honestly for your discharge run and think about a bigger pump or a second one if you've got a deep bilge or a long vertical lift. For most small boats though, this is exactly the right amount of pump. It's proven, it's affordable, and when a float switch or a flip of the helm switch calls for it, it moves water and keeps you dry.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul class=\"nvn-features\"\u003e\n  \u003cli\u003e500 GPH flow rate rated at a true 12V, closer to real onboard voltage than the old 13.6V rating\u003c\/li\u003e\n  \u003cli\u003eNon-automatic operation, runs off a helm panel switch or a Rule float switch for hands-off protection\u003c\/li\u003e\n  \u003cli\u003eHigh-efficiency, low-amp motor draws minimal current so it's easy on the battery\u003c\/li\u003e\n  \u003cli\u003eStainless-steel shaft resists corrosion in the wet bilge environment\u003c\/li\u003e\n  \u003cli\u003eFully submersible and ignition protected for safe use in gas-powered boats\u003c\/li\u003e\n  \u003cli\u003eBuilt-in thermal cell cuts the motor off if it runs dry and overheats, protecting pump and boat\u003c\/li\u003e\n  \u003cli\u003eBackflow preventer included so discharge water doesn't drain back into the bilge\u003c\/li\u003e\n  \u003cli\u003eAnti-airlock vent under each strainer tab bleeds trapped air so the impeller never spins dry\u003c\/li\u003e\n  \u003cli\u003eTrue electromagnetic (EMC) suppression keeps motor noise off your VHF and electronics\u003c\/li\u003e\n  \u003cli\u003eStandard 3\/4-inch hose outlet fits common bilge plumbing\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv class=\"nvn-trust\"\u003e\n  \u003ch2\u003eWhy Buy from NVN Marine\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eAuthorized Rule reseller, full manufacturer warranty\u003c\/li\u003e\n    \u003cli\u003eNMEA member and ABYC certified, advice from real boat techs\u003c\/li\u003e\n    \u003cli\u003eSame-day shipping before 3 PM ET on in-stock items\u003c\/li\u003e\n    \u003cli\u003eNY headquarters and Fort Lauderdale flagship retail store\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cdiv class=\"nvn-faq\"\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs the Rule 25DA automatic or does it need a switch?\u003c\/summary\u003e\n    \u003cp\u003eIt's a non-automatic pump, so it has no built-in sensor. You control it with a helm panel switch, a Rule float switch, or both. Most boaters wire a float switch for hands-off protection plus a manual switch at the dash for topping off the bilge before hauling out.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat size hose does the 500 GPH Rule pump use?\u003c\/summary\u003e\n    \u003cp\u003eThe discharge outlet takes standard 3\/4-inch bilge hose. Double-clamp the hose at the pump and run it up in a smooth loop to a through-hull above the waterline.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eDoes this pump include a check valve or backflow preventer?\u003c\/summary\u003e\n    \u003cp\u003eYes. This generation includes a backflow preventer so water sitting in the discharge hose doesn't drain back down into the bilge every time the pump shuts off.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWill 500 GPH be enough for my boat?\u003c\/summary\u003e\n    \u003cp\u003eFor tenders, jon boats, small center consoles under about 20 feet, and small sailboats, 500 GPH is a sensible primary pump. Remember that real flow drops as the pump lifts water higher, so if you've got a deep bilge or a long vertical discharge run, step up to a larger pump or add a second one.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs the Rule 25DA ignition protected?\u003c\/summary\u003e\n    \u003cp\u003eYes, it's ignition protected and fully submersible, so it's safe to install in the bilge of a gasoline-powered boat where fuel vapors can collect.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat voltage does it run on?\u003c\/summary\u003e\n    \u003cp\u003eIt's a 12-volt DC pump. Rule rates its 500 GPH flow at a true 12 volts rather than 13.6 volts, so the rated number is closer to what you'll actually get on a typical onboard system.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat wire should I use to install it?\u003c\/summary\u003e\n    \u003cp\u003eUse tinned, marine-grade wire with proper crimp connectors and fuse the positive lead per Rule's rating. Untinned automotive wire corrodes quickly in a bilge, and a corroded connection is the most common reason a pump won't run when you need it.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat keeps the pump from airlocking?\u003c\/summary\u003e\n    \u003cp\u003eThere's a small vent hole under each strainer tab that lets trapped air escape from the pump housing. That stops the impeller from spinning against a pocket of air and moving no water, which is a common failure on older bilge pumps.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eCan it run dry without burning up?\u003c\/summary\u003e\n    \u003cp\u003eIt has a built-in thermal cell that cuts the motor off if it runs dry and gets too hot, which protects the pump and the boat. Even so, it's not meant to run dry for long stretches, so pair it with a properly set float switch.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhere should I mount it in the bilge?\u003c\/summary\u003e\n    \u003cp\u003eMount it at the lowest practical point so it can pick up water, but keep it out of the sludge and debris that collect at the very bottom, since that's what clogs an impeller. A clean strainer base and a solid mount keep it pumping season after season.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable class=\"nvn-specs\"\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003cth\u003eTitle\u003c\/th\u003e\n\u003ctd\u003eRule 500GPH Standard Bilge Pump - 12V\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eRule\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eManufacturer Part Number\u003c\/th\u003e\n\u003ctd\u003e25DA\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eUPC\u003c\/th\u003e\n\u003ctd\u003e042237104717\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eFlow Rate\u003c\/th\u003e\n\u003ctd\u003e500 GPH\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eVoltage\u003c\/th\u003e\n\u003ctd\u003e12V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eOperation\u003c\/th\u003e\n\u003ctd\u003eNon-automatic (panel or float switch)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eHose Outlet\u003c\/th\u003e\n\u003ctd\u003e3\/4 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eShaft\u003c\/th\u003e\n\u003ctd\u003eStainless steel\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eMotor\u003c\/th\u003e\n\u003ctd\u003eHigh efficiency, low amp\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eIgnition Protected\u003c\/th\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eSubmersible\u003c\/th\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eThermal Protection\u003c\/th\u003e\n\u003ctd\u003eBuilt-in thermal cutoff cell\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eBackflow Preventer\u003c\/th\u003e\n\u003ctd\u003eIncluded\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eElectromagnetic Suppression\u003c\/th\u003e\n\u003ctd\u003eEMC compliant\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eAnti-Airlock Vent\u003c\/th\u003e\n\u003ctd\u003eYes, under each strainer tab\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eCategory\u003c\/th\u003e\n\u003ctd\u003eBilge Pumps\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eManufacturer\u003c\/th\u003e\n\u003ctd\u003eRule (Xylem)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n    \"@context\": \"https:\/\/schema.org\",\n    \"@type\": \"FAQPage\",\n    \"mainEntity\": [\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Is the Rule 25DA automatic or does it need a switch?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It's a non-automatic pump, so it has no built-in sensor. You control it with a helm panel switch, a Rule float switch, or both. Most boaters wire a float switch for hands-off protection plus a manual switch at the dash for topping off the bilge before hauling out.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What size hose does the 500 GPH Rule pump use?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"The discharge outlet takes standard 3\/4-inch bilge hose. Double-clamp the hose at the pump and run it up in a smooth loop to a through-hull above the waterline.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Does this pump include a check valve or backflow preventer?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Yes. This generation includes a backflow preventer so water sitting in the discharge hose doesn't drain back down into the bilge every time the pump shuts off.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Will 500 GPH be enough for my boat?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"For tenders, jon boats, small center consoles under about 20 feet, and small sailboats, 500 GPH is a sensible primary pump. Remember that real flow drops as the pump lifts water higher, so if you've got a deep bilge or a long vertical discharge run, step up to a larger pump or add a second one.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Is the Rule 25DA ignition protected?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Yes, it's ignition protected and fully submersible, so it's safe to install in the bilge of a gasoline-powered boat where fuel vapors can collect.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What voltage does it run on?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It's a 12-volt DC pump. Rule rates its 500 GPH flow at a true 12 volts rather than 13.6 volts, so the rated number is closer to what you'll actually get on a typical onboard system.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What wire should I use to install it?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Use tinned, marine-grade wire with proper crimp connectors and fuse the positive lead per Rule's rating. Untinned automotive wire corrodes quickly in a bilge, and a corroded connection is the most common reason a pump won't run when you need it.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What keeps the pump from airlocking?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"There's a small vent hole under each strainer tab that lets trapped air escape from the pump housing. That stops the impeller from spinning against a pocket of air and moving no water, which is a common failure on older bilge pumps.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Can it run dry without burning up?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It has a built-in thermal cell that cuts the motor off if it runs dry and gets too hot, which protects the pump and the boat. Even so, it's not meant to run dry for long stretches, so pair it with a properly set float switch.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Where should I mount it in the bilge?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Mount it at the lowest practical point so it can pick up water, but keep it out of the sludge and debris that collect at the very bottom, since that's what clogs an impeller. A clean strainer base and a solid mount keep it pumping season after season.\"\n            }\n        }\n    ]\n}\n\u003c\/script\u003e\n","brand":"Rule","offers":[{"title":"Default Title","offer_id":44925487808605,"sku":"64166","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0299\/7266\/0317\/files\/64166XL.jpg?v=1787378320","url":"https:\/\/nvnmarine.com\/products\/rule-500-gph-standard-bilge-pump-12v-25da","provider":"NVN Marine","version":"1.0","type":"link"}