Is my boat drive by wire or not?

[Skylar18]

Yes Mikey, I am upgrading to the GPS version. Wakeboard Pro to StarGazer.

Perfect Pass themselves on their web site says if you are on a river it is better to stay with a paddlewheel.

Doesn't make sense to me either as you would think the GPS would keep you at a relative speed the boat is travelling using calculations from the boat to the satellites and a paddle wheel would give you an inaccurate speed in a heavy current.

I don't get it but I'm not that bright....

[sybrmike]

I gave Mikey the treadmill analogy before - jogging on a treadmill at 10 mph, your handheld gps shows you're traveling 0 mph, but your legs, heart, & lungs definitely feel like 10 mph. It's the relative speed differential between the water and board/boat surface that make them plane and perform.

[Skylar18]

That makes sense. I didn't take into account that my "road" could be moving as well. That now seems so simple. Being on a lake, I really don't have a current that makes much difference.

[stinky_1]

So lets pretend I am on a river, and it has a current that is going 15 mph. If I tied my boat to the dock, let it get pulled till the line was tight and set my zero off for 15. Would the system try to accelerate me? The paddle wheel should in theory be going as fast as the current. So it should be happy I am going 15, even though my wakeboarder is not even out of the water.

consequently if I am going the other way, and I am traveling at 15 mph, and my zero off is set to 15, that paddle wheel should not actually be moving since the current is equal and opposite to my actual speed. So, zero off will be trying to speed me up. I would think my GPS speed would read around 30 mph, since I am losing 15 mph of readable speed with the paddle wheel.

I dont care how hard the system, motor or anything else is actually working, as long as my wakeboarder is going as fast as he would like.

So, obviously I am wrong here or they would not want everyone running a paddle wheel. But is this paddle wheel working in conjunction with the GPS to figure out how fast the current is? And at the end of the day why does it matter? if the boat needs to put more power down to travel 15 mph up the river, it will be travelling a true 15 mph relative to distance per hour. It will have no affect what the current on that river actually is. I still think that paddle wheel is not really doing us any favors here.

Can someone please explain where I am going wrong with this?

Also, sorry to hijack this thread.

[Skylar18]

Stinky,

Now you made my head hurt! I am going to have to suck it up and ask my wife, the physics teacher why a paddle wheel is preferred for a river with a current....I will never live this down.

On another note, I received my StarGazer today. Problem is they sent me the 3 event one, not the Wake. Since all I do is Wakeboard and Surf, should I have them switch it out for me? It looks like the 3 event is the more expensive unit, but might be more complex than what I need since we don't ever run a slalom course.

Or does it not really matter?

[sybrmike]

You probably understand better than I can explain, so I'll try again using your situations. Assume that what matters to the boarder is the speed of the water under his board (let's not get into how current affects the the boat wake). Think waterpark flowboarding where you can boogie board in place on a sheet of flowing water. Again, a handheld gps says zero but you're tearing up a wave.

So same thing as if you're on a river with 15 mph current and anchored facing upstream. Boat gps says zero, but boat paddlewheel says 15 mph and water's running under the board at 15 mph. If you pull anchor and travel upstream at a rate that the gps says 15, the paddlewheel will show 30 and the boarder will wonder why the shore is moving so slow (15 mph) yet the water's running 30 mph under the board.

Now turnaround & float downstream with no power with the current. The gps shows 15 mph, but boat and rider are just sittin there. You have to run the boat 30 mph downstream on the gps in order for the paddlewheel and rider to feel like 15.

Otherwise, just run around in circles, take the root mean square of the product of the gps and paddlewheel indicated speeds, divide by two, and subtract the effects of centripetal and centrifugal accelerations on the boarder, then simply adjust your speed relative to the gestures of the rider, & have a cold beverage after the run...