Second bilge

[SweeperForce]

I have a 25 years old open bow 18 foot v bottom ski boat. Because of the age I am replacing the fuel tank and bilge pump. I read that main bilge should be automatic around 750 gpm. And add a manual switch pump about six inches higher of 1000+ gpm in case of swamping. My question is: do I run both pump hoses to a T then exit at the original port or do I add another through the hull port. I guess to further answer my question, how water can fit thought a 3/4 ID inch hose? Could my 3/4 inch hose handle 1700 gpm verses a 1 or 1 1/2 " hose. Thanks, Tom

 

[GA_Boater]

First, you need to run both pump outputs through the hull separately. Second, place both pumps the same distance above the bilge, like Zero inches, as low as you can go. If the lower GPM pump can't keep up and the higher GPM pump is six inches higher, you lost the advantage of the bigger pump. Also, if the small pump fails, you will have a bilge full of water increasing the odds of further swamping. And finally, match the hoses to the pump output size to pump the maximum amount of water overboard. Hope this helps.

 

[Bondo]

Ayuh,.... Put the 1000 gal at the bottom on a 1, 1/8" hose, separate thru-hull for each pump,...

I agree, keep 'em both as low, 'n aft as possible/ necessary,....

 

[SweeperForce]

Thanks for all the replies. Lots of good advice here. I will keep both pumps level with each other and drill a separate discharge port for the new addition. Thanks again, Tom