Attwood 4140-4 WaterBuster® Portable Pump, Submersible, Battery Powered, 200 GPH, 42-Inch Hose, 5 ¼-Inch Diameter

Update: 8 years later (time flies), and this pump (plus a lot of carrying buckets back and forth) mitigated disaster yet again. My main sump pump failed this time causing water to backup in my basement, and this ran like a champ for the better part of 2 hours clearing the water while waiting for an emergency plumber to arrive.I bought this after my Sump Pump discharge line froze over the winter and I struggled with a manual siphon + buckets to empty my window well before the house flooded. A few nights ago the (same) pump burnt out during a rainstorm and I had to enact my 'emergency plan' to clear out the water.This pump worked perfectly. It takes a couple of minutes for it to completely fill a large contractors bucket (5 gallons I think?). I filled up 4 of those before my window well was cleared without any issues. The pump moves the most water when fully submerged, losing speed when the water level gets down to a few inches.The hose that comes attached to this pipe is relatively small, but uses a standard fitting. In my case, I connected it to an old washing machine hose to give it sufficient reach. The pump was sitting at the bottom of my window well, with the hose coming up and through the window, and the extension going down to a bucket on the floor (several feet below).Once the pump gets started in this configuration, it is aided by the siphoning effect. In fact, if you turn the pump off, water will continue flowing, albeit at a significantly slower rate.I can't attest to how this pump might perform if pumping entirely up, versus my simpler case of pumping up a foot and then down.My only complaints about the pump are:- It can be difficult to unscrew the top to install or change the batteries.- There is no battery-charge indicator. I plan on erring on the safe side and put in fresh batteries after each emergency use (and hope I don't need to use it for a long time but remember to check the battery in a few years to ensure it doesn't leak).- The power button would be better situated on top. When submerged and out of view, it can be tricky to find the button by feel.- Given the implicit siphoning action when turned off, it would be nice if a valve was included to stop the water flow (ie: when changing buckets). I will be picking up a cheap valve when I have a chance to keep with the pump.

Works as advertised. It's a bit slow but it's also battery operated so it's what it is.

The pump worked awesome right out of the box, I used it to pump rain water out of my 10' inflatable dinghy after a rain storm. Worked quick - never submerged it completely but the water level did reach the on/off push button. One week later I needed to pump out rain water from the dinghy once again. Pump would not start. I opened it and found condensation on the battery holder, I dried it and replaced the batteries but the pump still would not turn on. I did notice a small amount of water below the battery pack. When I put the lid back on the pump i noticed air bubbles coming out from behind the on/off switch. I opened the unit back up and removed the on/off switch and found that the manufacturer does not seal the switch, they seem to rely on a rubber boot that sits atop the switch holding nut. That seems to be where the water came in. A simple o-ring in between the switch and the housing would go a long way. I'm going to dry it out and try it again before I return it - hopefully the small pump motor has not been corroded by the condensation. But since it is supposed to be submersible and I didn't submerse it, and water still got in and it and only lasted for one use I have to give this 1 star. If i could give less than 1 star I would. I'll be adding an o-ring to the switch and If I can save the pump I'll update this post.

I love this little pump. However it was hell getting it open for the batteries. I struggled with it for 2 days. I am not strong so that had something to do with it. Also, the little tabs that hook to the battery are very fragile so be careful with them. there is a good Youtube video for opening and placing the batteries. After all of that it worked like a charm. I had one before that functioned for years, but was lost in a move.

Great pump for emptying aquarium. Does about 15 gallons in 5-6 minutes. This is my second unit. The first one lasted 13 years! Battery operated makes it convenient.