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Supra/Moomba Gravity III Ballast System Upgrade

Complete ballast system upgrade for 2002-2008 Supra and Moomba wakeboard boats includes everything you need.

  • Complete ballast system upgrade for 2002-2008 Supra and Moomba wakeboard boats includes everything you need.

Regular Price: $1,039.99

Special Price $939.99

Availability: In stock


A complete upgrade for solves all of the issues of the 2002-2008 Moomba and Supra boats equipped with the Gravity III factory ballast system.


Unfortunately, it's well known that the factory Gravity III ballast system installed in 2002-2008 Moomba and Supra boats has numerous flaws in terms of its design and functionality. Going back more than three years ago we pioneered the first Gravity III Ballast System Upgrade, and since then we've helped lots of unhappy owners fix the issues with the factory setup.

The next evolution of that upgrade is this complete package, which includes everything you need, pre-selected and guaranteed to work seamlessly to revamp the factory system that's currently installed in your boat. Our Gravity III Ballast System Upgrade includes everything you need to completely overhaul your factory setup in one convenient package that has been tested through countless installations.

After installation, which we've worked hard to make it as simple as possible, your boat's factory ballast system will essentially be upgraded to the 2009+ factory system which uses a dedicated reversible pump for each bag in the system. That means you can say goodbye to priming issues, slow and inconsistent fill times, and you'll also gain a dedicated vent/overflow connection for each bag. Get more weight in your boat in less time, and with no drama, just an easy to operate system that works like you expect every time.

How It Works

We reuse as much of the factory components as possible to offer value and ease of installation for our customers. Your factory ballast system uses a single common fill pump, which is a huge bottleneck if you are filling all three ballast locations, since the output of that pump is split in thirds.

Our upgrade replaces that single common fill pump with a dedicated pump for each bag that is responsible for both filling and draining the system. That means you have the full capacity of that pump available to fill each bag, drastically reducing the amount of time required to fill and drain the system.

How It's Installed

Although we've worked as hard as possible to make this upgrade as easy to install as it can possibly be, there are some aspects of the installation that are unavoidable. Let's just get this out of the way right off the bat:

Additional holes will need to be drilled in the boat. There's just no way around it if we're going to fix the problems that are inherent with the factory system.

We've been selling ballast systems for a long time, and our customers are, understandably, always intimidated by this step of the process. We have some great video guides available that demystify this step of the process, so although it's intimidating, if you know how to use a drill, it's not difficult. Of course you can always have your local dealer or marine service shop drill the holes for you if you would prefer (and we're happy to ship your order directly to them for installation).

Outside of the drilling the holes, the rest of the installation is fairly straight forward, and consists of mounting the new pumps, running new hose to feed the system, and wiring the new pumps to your factory switches. (Does not include instructions)

Click here to read our guide on installing Thru-Hull Fittings On Your Boat.


Any 2002-2008 Supra or Moomba v-drive boat with the Gravity III factory ballast system.

What's Included:

-Johnson Ultra Ballast Reversible Pumps -1" Ballast Hose Black -1" & 1-1/8" Stainless Steel Hose Clamps -3/4" Thread x 1" Hose Barb Fittings -1" Thread x 1" Hose Barb Fittings -Fly High 1" Flow-Rite Quick Release Connectors -Flow-Rite 1" Elbow Quick Release Connectors -12 Gauge Ring Terminals -12 Gauge Crimp Butt Connectors -12 Gauge Inline ATO Fuse Holders -30 Amp ATO Blade Fuses -12 Gauge 2 Conductor Marine Pump Wire -Pre-wired Reversible Pump Switch Connectors -1" Bronze Ball Valves -1" Bronze Mushroom Thru-Hull Intakes -Attwood Clear Silicone Marine Adhesive


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  • 4/29/2013
    Upgrade successful!
    jean-christophe The Kit is well thought. the end result is awesome.

    the 750 bags now fill up in about 5-6 minutes, which is about 1/3 of the time than before.

    that was a very fun project!
    It's really worth it, i don't regret at all.
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