I use one as a portable pump and it works OK- but it's really LOUD. I suspect it wouldn't last very long if run a lot. I originally intended to use it as a replacement for my raw water washdown pump but nixed the idea because it makes so much racket. I boat in freshwater and it looks fine after 3 seasons- no rust. In defense of these things, I gotta say that mine pumps fine and have found it useful in some creative ways: -clearing the bilge water after the built-ins are done -as an emergency pump on the water -as a washdown pump on the bow of the boat (my 25' hose won't reach from the source) -as a winterization pump for sterndrives and outboards (hooked to the muffs)