My pumpless ballast system.
Lemme start out acknowledging my friend Jim Aikens. This system was his brainchild. It took him a lot of convincing to get me to believe this system would work.
I was tired of messing around with ballast bags and getting pumps to siphon correctly. I asked Jim to start thinking of the schematics for a diy ballast system. Instead of the usual Jabsco pumps and electrical wiring, Jim suggested running a totally pumpless ballast system.
PHYSICS of the system.
Don’t know the exact name of the principle but its similar to the old trick we used to do as kids, placing your finger over a straw to retain water. We used vent control valves( to replace the thumb) at the end of the “straw”. The valves are dual purposed. They allow the system to drain or fill when opened. Open the valves to allow water to enter the tanks (boat must be moving) and close them once they are full to retain the water. When you want to drain the system. Stop the boat and open the valves. The tanks are above the water lines and drain naturally.
This is a picture of the valves. ¼ barbed valves. Purchase at Mcmaster Carr. Location of the install is the box just to the right of my throttle.
At the bottom to the boat we used a scooper to bring the water into the tanks. Jim owns a SAN and said he rarely uses the pumps to fill his system. However he has two or three scoops. I opted to go with one on my boat and we both were a little skeptical of the fill times. The scooper I got on ebay for about 25 bucks.
This is the other side of the scooper and the valve. I got the parts for the T at a local farm store. I couldn’t find the stuff at lowes or home depot. I used a braided reinforced hose to
prevent kinks. The hose attaches to the T with barbed fittings that screw into the T. and hose clamps are used as well. We attached a ball valve to the top of the scooper. In case there is ever a leak I can just turn the ball valve off.
This a photo of the front(triangle tank) and rear tanks. It is made with stainless steal. It has a fitting at the bottom of the tank for the main fill/drain hose and as a small fitting at the top for the overflow on/off valve. When the tanks fill up water shoots out of the overflow hose and I turn off the overflow valves as pictured above to prevent any more water entering the system. When im ready to empty I just open the valves and let the system drain. The boat must be going pretty slow though(under 5 or 6 mph)
photo of the rear tank. Sorry for the quality.
the fill/drain hose is run under the floor and attached to the fitting of this tank that is near the gas tank at the back of the boat. The overflow hose is run up the left(in this photo), driver’s side rail. Mastecraft has pvc pre-routed underneath the rail for wires etc and the small tubing fit just as well.
This is a photo of the overflow holes. Also of my diy tower mounts that ive never gotten around to painting. Those are just behind the driver on the right side of the boat 1/4 tubing(size of my overflow tubing) was welded to a small plate and then holes drilled into the plate. I used silicone to attach the plate and on the backside the hose clamps hold it in place as well.
This last photo is just of the pad I had made for the back tank. I’m going to cover the front of it one day I’m just not sold on one particular idea. I’m thinking of carpeting with netting so I can store my rope or a jacket or two. I’m also going to add handrails as well.
So the system works really well. It fills in 5 ½ minutes. And drains quickly as well. Though I’ve never timed the drain. I would guess about the same. This obviously isn’t for everyone. I had to sacrifice boat space for the tanks. However I feel like ive actually gained a lot of space. I don’t have to haul around a fat seat and a fat sac along with two pumps. Not to mention having to deal with draining and filling the sacs which to me is a royal pain the butt. The tanks cost me 350 dollars and the other parts cost about 150 dollars. All hoses and barbed fitting were purchased at mcmastercarr.com
My system holds about 1100 pounds once full. I also have about 500 lbs in iron(obtained at a metal recycling center for 40 bucks)
im also forwarding Bill a copy of the spreadsheet that has several tank shapes. You can manipulate the size of the tanks to any dimension and it will give you the weight of the tank once full of water.
these are the links to the discussions on wakeworld
if you need to contact me feel free to do so at if I cant answer your questions ill put you in touch with jim.