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  1. Bilge Pumps
  2. Seaflo
  3. Automatic Bilge Pumps
  4. Submersible Pump
  5. 750 GPH
  6. 3/4 Inch Diameter
Seaflo Automatic Bilge Pump w/ Magnetic Float Switch - Submersible - 750 GPH - 3/4" Drain

Seaflo Automatic Bilge Pump w/ Magnetic Float Switch - Submersible - 750 GPH - 3/4" Drain

Item # SE77FR
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Our Price: $38.45
Bilge Pumps
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Shipping Weight: 1.37 lbs
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Get ultimate peace of mind when you're out on the lake and when you're docked. Submersible, motorized pump with built-in float switch automatically removes excess water from the bilge wells in your boat so you can focus on relaxing. 1-800-940-8924 to order Seaflo bilge pumps part number SE77FR or order online at Free expert support on all Seaflo products. Guaranteed Lowest Price and Fastest Shipping for Seaflo Automatic Bilge Pump w/ Magnetic Float Switch - Submersible - 750 GPH - 3/4" Drain. Bilge Pumps reviews from real customers.
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Seaflo Bilge Pumps - SE77FR

  • Automatic Bilge Pumps
  • Submersible Pump
  • 750 GPH
  • 3/4 Inch Diameter
  • Seaflo

Get ultimate peace of mind when you're out on the lake and when you're docked. Submersible, motorized pump with built-in float switch automatically removes excess water from the bilge wells in your boat so you can focus on relaxing.


  • Automatic pump removes water from your boat's bilge
    • Lets you keep your boat docked in the water without having to worry about water building up in your absence
  • Built-in, magnetic float switch turns pump on and off automatically
    • Turns on when water level rises to 2" above the bottom of the intake screen
    • Turns off once the water level reaches 3/4" from the bottom of the intake screen
  • Removable strainer prevents leaves and debris from entering the pump
    • Quick-disconnect function allows for easy cleaning
  • Compatible with 12V DC systems
  • Strong ABS plastic exterior protects internal components


  • Overall dimensions: 3-1/4" wide x 6-1/2" long x 4-1/8" tall
  • Drain nozzle: 3/4" inner diameter
  • Maximum power draw: 5 amps
  • Flow: 750 gallons per hour
  • Maximum water temperature: 110 F
  • 4-Year limited warranty

Note: A panel switch (sold separately) will be required to operate this pump. This pump cannot pump oil. It will not turn on if straight motor oil enters your bilge.

In simplest terms, a bilge pump works to remove water from your boat so that your ship doesn't sink. The number of pumps needed to do this depends on the size of your boat. Larger boats may have 2 to 3 bilge pumps installed at different heights within the bilge, while a smaller fishing boat may only have 1.

Automatic Bilge Pump

There are 3 types of bilge pumps available: manual, non-automatic, and automatic. Manual pumps are human-powered, and no one wants to be constantly monitoring their boat and pumping out water on their day off. Non-automatic pumps turn on with the flip of a switch, but they still require your attention. And they can be a hassle if they're not meant for your type of boat.

This Seaflo bilge pump is automatic, so once you install it, you don't have to do a thing. It will work on any boat, but it's ideal for those where the bilge is hard to access, so you need a pump that can be out of sight and out of mind. It will kick on when it detects water in the bilge and kick back off when the water level has gone down to an appropriate level, letting you cove out or fish without having to worry about water gathering in your bilge.

Quick Tip: If you hear this automatic bilge pump kicking on often, you may want to confirm that the plug is in your boat.

This pump is also great to have if you're docking in an uncovered slip because it will remove any rainwater that collects in your boat, letting you store your watercraft without worry.

How Does a Float Switch Work?

The automatic functioning of this pump occurs thanks to the included magnetic float switch.

When water enters your bilge, the internal float will rise. It has a small magnet inside that, when it gets close enough to the switch, will draw the 2 metal reeds in the switch together. This closes the electrical circuit and causes the pump to turn on. When the water level drops, the magnetic float drops as well so that the reeds stop touching. This will cause the bilge pump to turn off.

Installing a Bilge Pump

If your bilge pump has gone bad and you need to replace it, installing a new one should be as simple as disconnecting the old pump and connecting this new one in its place. If you need an extra pump in your boat, or if you are installing one for the first time, you may need to affix a bracket or steel plate to your boat so you have something to mount the bilge pump to.

Disconnected strainer snaps back on

To mount this Seaflo pump, just pop off the strainer and attach it to your mounting point. Once mounted, the top of the pump simply snaps back into place on the strainer portion.

A thru-hull port (sold separately) will be needed for each bilge pump to drain water through. This will need to be installed in the hull, above the waterline and within 11' 2" of the pump. Keep in mind, the more water your pump has to push upwards (head), the lower your flow rate (or GPH), will be. If you measure from your bilge pump placement up to the height of your thru-hull, you can use the chart below to determine approximately how many gallons per hour you can expect this pump to move.

Output flow diagram

To route water up through the port, this pump requires 3/4" inner diameter tubing (not included) that secures to the drain nozzle with a clamp.

Product diagram

This pump has a 3' long, 3-lead wire that will connect to your power source. Wiring this pump to a switch is required.

Wiring code:

  • Black - negative
  • Brown/white - automatic mode
  • Brown - manual mode

Wiring diagram

SFBP1-G750-11 Sea Flow 11-Series Automatic Bilge Pump w/ Magnetic Float Switch - Submersible - 750 GPH - 3/4" Outlet

Video of Seaflo Automatic Bilge Pump w/ Magnetic Float Switch - Submersible - 750 GPH - 3/4" Drain

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Seaflo Automatic Bilge Pump with Magnetic Float Switch Review

AJ: What's up everybody It's AJ with Today we're checking out this bilge pump from Seaflo. Now, this one works at 750 GPH, which is gallon per hours. That doesn't mean much to me when I say it out loud, so let's just put it in the water and check it out, huhWhat it's going to do is help you get that excess water out of your boat. Now, this one happens to be an automatic. Can you see, when I take it out of the water it stops, and it's not pumping water anymore.

It has a switch on the inside that floats up when it detects the water and starts pumping it out. This would be great for an early detection, if you forgot to put your plugin and you launched your boat. Also, when there's a bunch of water coming out and you hear the pump get going, and you go, "Oh no, I got to plug it up."You see, it stopped on its own once it got to the bottom. A little bit of water is going to be normal in your boat. You can't get all of it, and that way it's not always going to be running either.

It can stay in there with just a little bit of water. It's not going to bother it.Now I did say it was an automatic bilge pump. There are other ones that don't automatically turn on. They're switch based, so you would connect it up to the always on power source, and it's up to you to turn it on to pump the water out.I just wanted to show you how it worked. This is that float switch on the inside.

When the water's in there, it'll float up to the top and it'll power up the fan, so that way it's wired up. It's not always running. You don't always have to think about it. It kicks on when you need it to.Another few things to think about is, if you're going to replace one or add one to your boat If you're replacing it, great, you already know where the wiring goes to. You probably already have a hose run, so you're good.

Now, if you're adding one to your boat, along with an existing bilge pump, you're going to have to get the hose separately. It doesn't come with one. Now, this one works with 3/4" diameter on the inside of the hose, so that's what kind it's going to fit. I would recommend getting some more hose clamps, or if you have them, secure it down that way, and not to mention some heat shrink butt connectors, so when you're wiring it up, you can make sure you use the heat on there, shrink them down. They're nice and sealed, so that no water is going to mess it up.What does gallons per hour really mean This one's 750. I can rattle off all the other numbers, but that doesn't help me explain to you how fast it actually goes. Everybody's got different boats and they're going to use these for different things, so we're going to use them side by side to show you just how much time they save.Here's the plan. We're going to pour 10 gallons into this container. I'm going to do that with every bilge pump to make sure we have the same amount of water, and then we can time it and see how quick it takes to pump it out.(silence).Stop.Done.Done.Done.That's pretty cool to see them right in a row, and they actually do make a big difference. They don't just have the numbers on there for no reason. Our lowest one, our 500, was 50 seconds, and the highest one, at 2000 was 22 seconds, so that's a big difference. We saw that change with each one we used. One thing I will note though, is the sound sure didn't change too much. They sounded about the same, especially when it was submerged in water. Of course, it gets noisier when there's no water. You can hear it right before it shuts off, but most of these are going to be down, tucked away somewhere in your boat, so they're not going to be right in front of the steering wheel and your face. You're barely going to hear it when it's going in your boat, pumping that water out.One of the biggest differences for me is the switch based ones versus the ones that have that auto switch. You can see, again, as this water raises up, it'll lift this up and engage it. I think that's just a better way to go about it. Not have to worry about flipping the switch, or what if I forgot to do it, then the back of my boat floods. Once this starts going up, it's going to pump that water out. That way it never builds up on you.Whichever one you go with, it's going to get the job done. We saw that they just go a little bit faster. It's way better than using a manual pump or a bucket. I'd much rather have this do the work for me. I think that does it for our look at these bilge pumps. Hope that helped.


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Info for this part was:

Employee Andrew K
Installed by:
Andrew K
Employee Jeff D
Installed by:
Jeff D
Employee Lindsey S
Edited by:
Lindsey S
Employee Chris R
Video Edited:
Chris R
Employee Alexander C
Written by:
Alexander C
Employee Aidan B
Video by:
Aidan B
Employee Sabrina W
Updated by:
Sabrina W

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