Ran some ballast experiments on our Challenger 2000...

[WAJetboating]

We filled two 30+ gallon trash cans with water, yielding ~500 pounds of movable ballast. We also had a topped-off fuel tank. We drove around at various speeds, shifting the weight around and videoing everything. Back at the house, we downloaded the videos so we could do side-by-side comparisons.

Interesting and unexpected results. A few highlights:

* Adding weight actually worsens the wake at a standard wakeboarding speed of 20MPH. It appears the heavier hull sort of "irons out" the wake at higher speeds.

* Moiving the weight around didn't seem to affect the 20MPH wake very much. It obviously affected how fast we planed out, but once planed there wasn't much difference.

* Adding weight definitely improves the possibilities for wake surfing. Shifting the weight rearward and to port, plus having two adults sit on the port gunwale, created a surprisingly nice green wave at about 12.5MPH on the speedometer. It was a bit short lengthwise but had plenty of height. I've read that adding ballast to the front of the boat tends to lengthen a surf wave, so that will be a followup experiment.

Not a lot more hard data yet, but the experiments continue!

 

[seadoosnipe]

Good idea!...

We filled two 30+ gallon trash cans with water, yielding ~500 pounds of movable ballast. We also had a topped-off fuel tank. We drove around at various speeds, shifting the weight around and videoing everything. Back at the house, we downloaded the videos so we could do side-by-side comparisons.

Interesting and unexpected results. A few highlights:

* Adding weight actually worsens the wake at a standard wakeboarding speed of 20MPH. It appears the heavier hull sort of "irons out" the wake at higher speeds.

* Moiving the weight around didn't seem to affect the 20MPH wake very much. It obviously affected how fast we planed out, but once planed there wasn't much difference.

* Adding weight definitely improves the possibilities for wake surfing. Shifting the weight rearward and to port, plus having two adults sit on the port gunwale, created a surprisingly nice green wave at about 12.5MPH on the speedometer. It was a bit short lengthwise but had plenty of height. I've read that adding ballast to the front of the boat tends to lengthen a surf wave, so that will be a followup experiment.

Not a lot more hard data yet, but the experiments continue!

That's a good idea, trying to figure out the proper weight displacment to make your boat a "wake". Since, the wakes use an onboard ballast, using a movable ballast would be worth a try.

You don't state what boat you are experimenting with but I see in your avatar that you have the 240 equipped boat.

Question? If you find this works, will it only be for that specific boat or do you think it can be tried in say, the 1800 Challenger?

 

[WAJetboating]

Question? If you find this works, will it only be for that specific boat or do you think it can be tried in say, the 1800 Challenger?

The hulls are different lengths so there might be some differences, but I'd think the basics would be applicable to either.

 

[slide00]

You need more water! I've got 2 500lb the boat came with in the back, a 500lb all the way up in the front of the ski locker that I use for weight and a fresh water tank, and I just put a 500lb in the back half of the ski locker that I'm going to put a t splice in my on board ballast pump to fill it with river water. It puts out a very nice wake.