Jump to content

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

Sign in to follow this  
like a bu

Perfectpass - How Does Stargazer Get The Waterspeed Correct If There Is A Current In The River?

Recommended Posts

like a bu

I need to install a PP in my "new to me" (used) '04 lsv I just bought. Any coaching out there from you wily veterans? Stargazer seems to be the latest thing, but I dont see how it would get the surface speed correct if there was any significant current? Should I put in a paddle wheel version?

Share this post


Link to post
Oberon

It doesn't. If you need to account for current speed get the paddle wheel version.

Share this post


Link to post
martinarcher

It doesn't. If you need to account for current speed get the paddle wheel version.

:plus1: It will be giving you speed across the bottom, not speed across the water.

Share this post


Link to post
cstk421

Unless I am reading the question wrong my answer would be yes. It makes no difference, current / direction of stream or not, the stargazer (GPS like i have) reads position according to where you are on the planet. If anything the paddlewheel is the wrong way and will definitely give you the wrong reading. Just my .02.

Thanks

Claudio

:plus1: It will be giving you speed across the bottom, not speed across the water.

Share this post


Link to post
Lieutenant Dan

What is important to the performance of your ski or board is the relative velocity between the "board" and the surface of the water. That is what the paddlewheel measures. GPS velocity is "absolute" velocity with respect to the "static" surface of the earth. Therefore, if you are riding on a body of water with a current, you need the paddlewheel to measure the relative velocity.

Of course, you could always approximate the current speed, then add that to the GPS speed you want to travel downstream and subtract it going upstream...

Share this post


Link to post
CedarLakeSkier

I completely understand everyone's question about this and I understand the differences between GPS and Paddlewheel.

What I don't understand is this. If you were having a competition somewhere where there was a current (like on a river) they don't make allowances for the current. You need to get from boat guide to boat guide (a specific fixed distance) within a specified period of time. This is exactly what GPS does.

I understand they probably wouldn't have a tournament in these conditions, but the principle is the same.

So my question is why would people prefer the paddlewheel? Is this just for free skiing?

Share this post


Link to post
like a bu

Its amazing no one has had this discussion before. 2 knots of current (which isnt unreasonable) makes a huge difference in tournaments. im long past my comp years (5 spine surgeries to prove it :)) but i can still tell a big diff between 20 mph and 22 mph. im also a pilot amd know that this is same physical challenge as true ground speed vs true airspeed. im going paddlewheel. life and rides will be a whole lot better.

Share this post


Link to post
edwin

The discussion has certainly taken place. It's little bit of a challenge, but for a pilot it should be an easy adjustment. We ride in the current pretty often and it's never been an issue. Just set SG for the desired speed and take a bit out when going up stream, add a bit when going down.

I used PP with a paddle wheel from 2000 to 2008, GPS based SG since then. IMHO, the SG is the way to go.

Share this post


Link to post
spinxt

My bu doesn't have PP, but I have one buddy with Stargazer and another with a traditional paddle wheel...we have this discussion often. All I can say is this...there is a noticeable difference between the two. (on our river). But it's all about consistency. It doesn't bother me to ski either if I'm getting pulled by the same boat. If I start swapping pulls during the same outing (which happens) it does mess with my head a bit.

Share this post


Link to post
mswsetter00

I know it's an old thread just thought I would add .02 for any future person researching.

I have a 2000 Wakesetter VLX with stargazer PP. I ride the Mississippi river, wish I had the paddle wheel. The current in the river is never the same. I'm always telling wife to speed up slow and slow down. One day it was so bad the boat didn't know what to do, the current was about 3.7mph that day. I just stopped ridding that day, because it would have right speed, but by the time I edged in it would have slowed down and wake was a wash or speed up and jerked me over wake. Different places on the river have different current. Not to mention when I fill rear fat-sacs full it can't keep a speed at all. I have been adjusting settings trying to get it to work and I have tried using the rpm as well. The PP worked well when I was on a lake with relatively no current, but still struggled with extra weight.  

Share this post


Link to post
05hammerhead

So this is of course a dumb question but Ive never thought of it before. 

If one was racing buoys on the river, wouldnt you benefit from the slower boat speed while still having a faster ski speed?  Or do you need to speed of the boat to get you the speed out to the bouy?  If thats the case, would it make it harder to make the buoys? 

Share this post


Link to post
Joeprunc

To shed light on this thread...PP Stargazer is amazing, I ski on rivers and the delta where there are always currents.  If you want to ski up river at 21 mph, and there is a 3.7 mpg current, set the PP speed to 17.3 mph, or if you are going down river set the speed to 24.7 mph.  I also have a paddle wheel on our boat, so I can adjust it on the fly.  If you are having a hard time getting the boat to keep speed with weight, I'd consider seeing if a different prop will help out.

If you don't have a paddle wheel, download a speed app on your phone, and float on the river to see what the current is moving at, then adjust your PP accordingly.

Share this post


Link to post
hethj7
On ‎9‎/‎9‎/‎2016 at 9:03 AM, mswsetter00 said:

I know it's an old thread just thought I would add .02 for any future person researching.

I have a 2000 Wakesetter VLX with stargazer PP. I ride the Mississippi river, wish I had the paddle wheel. The current in the river is never the same. I'm always telling wife to speed up slow and slow down. One day it was so bad the boat didn't know what to do, the current was about 3.7mph that day. I just stopped ridding that day, because it would have right speed, but by the time I edged in it would have slowed down and wake was a wash or speed up and jerked me over wake. Different places on the river have different current. Not to mention when I fill rear fat-sacs full it can't keep a speed at all. I have been adjusting settings trying to get it to work and I have tried using the rpm as well. The PP worked well when I was on a lake with relatively no current, but still struggled with extra weight.  

Boat looks familiar :).  Are you Michael?  This is Jason.  Glad to see it running strong for you this summer - sorry I didn't buy the paddlewheel version back in the day!   Wish I could help on your speed issue, but I always rode the lakes around here and didn't have to fight the current issue. 

Share this post


Link to post
MadMan
On ‎9‎/‎9‎/‎2016 at 9:12 AM, Joeprunc said:

 If you want to ski up river at 21 mph, and there is a 3.7 mpg current, set the PP speed to 17.3 mph, or if you are going down river set the speed to 24.7 mph.

This seems like it should be  taken care of automatically by the Perfect Pass.  It is a GPS, so it can tell if you are going up or down river and you could go into a cal mode where it measures the speed of the current.

Share this post


Link to post
hethj7
10 minutes ago, MadMan said:

This seems like it should be  taken care of automatically by the Perfect Pass.  It is a GPS, so it can tell if you are going up or down river and you could go into a cal mode where it measures the speed of the current.

I don't think it works like that.  I'm not sure how the GPS would be able to find the current speed to adjust.    It just as stated above - relative speed between the boat and the running surface and absolute speed across the earth (which the GPS measures).      3 MPH current + 21 MPH boat speed means you are headed down the river at 24 MPH absolute, but 18 MPH relative to the water surface.  Going up river, you're the exact opposite - 18 MPH absolute, but 24 MPH relative to the water's surface.  

If you want to ponder on it more, it is the same as a fly that is flying around in your car - it's running 70 MPH absolute and that is what a GPS would read if on the fly.  

Share this post


Link to post
MadMan
26 minutes ago, hethj7 said:

  I'm not sure how the GPS would be able to find the current speed to adjust.   

It would find the speed exactly how you would.  You stop the boat, put it in cal mode, and it would measure the speed.

Share this post


Link to post
hethj7

Hmm, never thought of that.  It would seem simple enough to implement, assuming most people don't have changing currents all the time. 

Share this post


Link to post
MadMan
9 minutes ago, hethj7 said:

Hmm, never thought of that.  It would seem simple enough to implement, assuming most people don't have changing currents all the time. 

Actually I have never even been on a boat with Stargazer, mine has a 16 year old paddle wheel Perfect Pass that works great. 

The river that we boat on current speed changes day to day.

Share this post


Link to post
Ronnie
51 minutes ago, MadMan said:

It would find the speed exactly how you would.  You stop the boat, put it in cal mode, and it would measure the speed.

When our river is running fast, you most times can't measure the speed of the current unless it is flat calm because the wind is giving you an incorrect reading. The wind will drift you in any direction without regard to the current speed under you.

 

Share this post


Link to post
waterskater

Why does it matter?  The skier speed is relative to how fast the water goes by the boat.   The current should only change how fast the shore (land) goes past the boat.  Right?

 

Share this post


Link to post
MadMan
3 hours ago, waterskater said:

Why does it matter?  The skier speed is relative to how fast the water goes by the boat.   The current should only change how fast the shore (land) goes past the boat.  Right?

 

The problem is GPS (Stargazer) is referencing the boats speed to the land, not the water.

Share this post


Link to post
waterskater

Ahhh...  Sorry, old school here.  You kids and your new dangled gizmos.... :blush:.   Am the same with fishing,. A fish finder is a rod and reel and some bait.   When I was a kid....

 

Share this post


Link to post
mswsetter00

Yeah, this is Michael. Not hating on you Jason, just putting it out there if you mainly run rivers you want paddle wheel. Madman, I have put it in neutral and measured speed as long as calm. However it changes when you go back up stream, have to remind wife of that every time she turns me around. Also different rivers have different currents. It makes a difference if in channel or in back water, normal pool, vs high or really low. Point is the stargazer is great for boats w/o a paddle wheel on a lake. Not so great for Mississippi river. I was adjusting KDW tonight while on Rock River and it seemed to do better. I'll be back on Mississippi tomorrow night. Believe me I would much rather ride lakes but there aren't too many on my area. So I'll deal with it for now.

Share this post


Link to post
MadMan
7 hours ago, mswsetter00 said:

Yeah, this is Michael. Not hating on you Jason, just putting it out there if you mainly run rivers you want paddle wheel. Madman, I have put it in neutral and measured speed as long as calm. However it changes when you go back up stream, have to remind wife of that every time she turns me around. Also different rivers have different currents. It makes a difference if in channel or in back water, normal pool, vs high or really low. Point is the stargazer is great for boats w/o a paddle wheel on a lake. Not so great for Mississippi river. I was adjusting KDW tonight while on Rock River and it seemed to do better. I'll be back on Mississippi tomorrow night. Believe me I would much rather ride lakes but there aren't too many on my area. So I'll deal with it for now.

How much adjusting do you have to do with Stargazer on a river?

Share this post


Link to post
mswsetter00

You just have to keep adjusting the speed. Then if the weight is causing issues you have to adjust the KDW up or down depending on the how the PP is engaging and taking control. It overshoots really easy on the river. It's just annoying to always have to be adjusting speed. Slow down to go up, and speed up to go down. In some areas I have a really short run so by the time it's good it's time to turn around again.  I'm trying to teach driver to look at wake and adjust speed accordingly.  It's just one of many things I dislike about river riding. As I stated it's where I live and I'll have to put up with it for now. Maybe one day I'll have that lake home and won't have to worry about it. I do need some bow ballast really bad. 

Share this post


Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...