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ski_king
03-16-2007, 09:00 PM
I was loooking thru the April issue of WaterSki Magazine and I saw a add for a GPS based speed control.
http://www.zerogps.com
http://www.zerogps.com/images/elite_medium.jpg
Anybody know anything about it?

JKTX21
03-16-2007, 09:08 PM
That's wild. Why send your boat speed to the moon when you can have a paddlewheel? :)

Farmer Ted
03-16-2007, 09:09 PM
I was loooking thru the April issue of WaterSki Magazine and I saw a add for a GPS based speed control.
http://www.zerogps.com
http://www.zerogps.com/images/elite_medium.jpg
Anybody know anything about it?

lots of hype but nothing substantial yet,

only works with DBW boats,

supposed to give a better pull than PP because it only loads the engine when the skier pulls,

hopefully it will be cheaper than PP and cause them to loose some market share and lower prices....

JohnnyB
03-16-2007, 09:10 PM
Find anything on pricing or accuracy???

EDIT: $1200 and some change for a unit...may as well go PPass

Farmer Ted
03-16-2007, 09:13 PM
That's wild. Why send your boat speed to the moon when you can have a paddlewheel? :)


GPS doesn't transmit, receive only

Here's a pretty good description of how it works, it's on the internet so it's got to be true:D


http://www.nasm.si.edu/gps/work.html

Farmer Ted
03-16-2007, 09:19 PM
Find anything on pricing or accuracy???

EDIT: $1200 and some change for a unit...may as well go PPass


if I understand this system correctly, you simply plot the entrance gate and the exit gate as waypoints and you're set

since DOD stopped introducing error into GPS it's very accurate

Footin
03-16-2007, 09:23 PM
We need to see a price war with PerfectPass.

erkoehler
03-16-2007, 09:26 PM
We need to see a price war with PerfectPass.

WHAT!:mad:

bigmac
03-16-2007, 09:36 PM
Find anything on pricing or accuracy???

EDIT: $1200 and some change for a unit...may as well go PPass

They do have a non-GPS version that uses the paddlewheel. It's only $690.

The whole product seems a little...preliminary...not much sales info on their website. Looks like it's going to take a telephone call to get the scoop.

east tx skier
03-16-2007, 09:36 PM
When it's adopted by the water ski community in toto, I'll upgrade.

Footin
03-16-2007, 09:38 PM
WHAT!:mad:

Just kiddin Erk, you know what i mean.

bigmac
03-16-2007, 09:39 PM
When it's adopted by the water ski community in toto, I'll upgrade.Toto too?

.

east tx skier
03-16-2007, 09:42 PM
Toto too?

.

The system has to be in toto.

Footin
03-16-2007, 09:43 PM
Toto too?

.

There's no place like home, there's no place like home.

ilikeitglacy
03-17-2007, 08:33 AM
if I understand this system correctly, you simply plot the entrance gate and the exit gate as waypoints and you're set

since DOD stopped introducing error into GPS it's very accurate
i can understand the course fonctions but how does it work outside the course ?:confused:

Ric
03-17-2007, 08:48 AM
what the hell I love buying gadgets for my boat so I can sit at work and talk about them :mad:

[clicking my feet right now]

WTRSK1R
03-17-2007, 10:06 AM
I agree that some healthy competition is generally a good thing for prices. However in this case, I would not want to be an early adoptor. Look what happened with Accuski. I would not want to spend $1200 and then find out that the whole business is gone in a year or two. PP works well, is easy to use, and a well established business that provides great customer support and continuos improvement in their product. I would give this a couple of years just to see where it goes.

:twocents:

G-man
03-17-2007, 10:14 AM
What major brand of ski boat will be the first to use this system? It will be interesting to see.

Ric
03-17-2007, 10:16 AM
G, my kids texted me from sea world yesterday to tell me they went to the ski show. She said, "dad we saw the ski show but they have nauticas!"

bigmac
03-17-2007, 10:19 AM
i can understand the course fonctions but how does it work outside the course ?:confused:
Same as Perfect Pass...the measured speed is used to control a servo motor on the engine throttle. IIRC, these first versions of Zero Off are only available to boats with built-in speed control, such as MasterCraft MCX 2005 model year and after.

As to slalom courses, I don't know. From a positioning standpoint, my Rino 530 is accurate to about 30-50 feet, typically. Some times of day I've seen it down to 15 feet. In WAAS mode, 10-12 feet is pretty common, but ability to get better accuracy out of WAAS, or even hit those satellites at all, depends on lattitude and some terrain features.

I don't know if typical GPS positioning accuracy is good enough to run a slalom course or not by plotting entrance and exit waypoints. It would take another cup of coffee before I could sit down and figure out whether a 20 foot positioning error would affect course speed and timing enough to DQ a run but it seems unlikely that they would bring a product to this market if it totally didn't work. Even so, I wouldn't be first in line to buy it if I had the slalom course in mind.

My suspicion, however, is that running a slalom course isn't the bulk of sales. Perfect Pass sells far more Wakeboard Pro than Digital Pro, so I'll bet that the main market for Zero Off, like Wakeboard Pro, is accurate speed control for wakeboarding/hydrofoiling. In that regard, position-averaging algorithms make GPS speed measurement accurate to about 0.1 mph, which is about the inherent accuracy of the Faria electronic speedometers currently used in our boats. I suppose it's worth noting that even Perfect Pass recommends calibrating their units using GPS. I think it's a cool idea for speed control. It eliminates the problems with paddlwheel placement, which is a problem at MasterCraft.

I'll bet Zero Off would work pretty well for a boat even if it didn't work great for a slalom course. The things that mostly affect GPS accuracy like tree cover and thunderstorms wouldn't really apply. I'd be curious to see what kind of servo mechanism they come up with for older, non-MasterCraft Cruise applications, if and when they do. My Perfect Pass servo has been accurate and reliable, but I confess I was a little put off by the concept of my $1000 speed controller being mostly a half-enclosed aluminum box with a string glued to a knob and hose-clamped to an exhaust hose....functional, yes...but not exactly elegant.

WakeSeeky
03-17-2007, 12:26 PM
I think it's a cool idea for speed control. It eliminates the problems with paddlwheel placement, which is a problem at MasterCraft.


Funny, we were just looking at this last night. I think it would be cool to be able to plug in a speed without mentally going through the calculations to guestimate the RPM setting. We pretty much gave up on the PP mph setting a long time ago, with the paddlewheel placement it just doesn't work well. It's a little thing, but that first pull always seems to take some dialing in for that day's conditions. I would really like to be able to just give it a speed and not think about it again.

bigmac
03-17-2007, 12:39 PM
Funny, we were just looking at this last night. I think it would be cool to be able to plug in a speed without mentally going through the calculations to guestimate the RPM setting. We pretty much gave up on the PP mph setting a long time ago, with the paddlewheel placement it just doesn't work well. It's a little thing, but that first pull always seems to take some dialing in for that day's conditions. I would really like to be able to just give it a speed and not think about it again.
I can pretty much do that on our lake - I hydrofoil in wakeboard mode by setting 21 mph. It works well most of the time, but chop or rollers will cause some "hunting" for speed maintenance as the too-forward paddlewheel placement picks up the turbulence. It's not been a huge problem for me, but I hydrofoil on glass most of the time and I'm guessing you don't get that luxury on Lake Mead. I've had some success dealing with those issues by changing the PP sampling rate and sensitivity on the paddlewheel (I can't remember where I finally set it). I'm sympathetic to the problem because +/- 1-2 mph speed variations can be highly annoying on a hydrofoil.

It might be cheaper for you to consider moving your paddlewheel to a more appropriate position, further back on the hull. IIRC, MYMC has some thoughts on that and perhaps he could give you some advice.

In the meantime, GPS-based speed control definitely has some attractive concepts...

WakeSeeky
03-17-2007, 12:51 PM
Well, sometimes we get glass, just don't tell anybody. :D

Probably our biggest variables are number of people and speed. We might have anywhere from 3 to 8 people (and their gear) and speeds might vary from around 19 to over 26. Depends who we're riding with that day. Once you get a base dialed in on the first ride, it's pretty simple, but I always have to play with it for that first pull or two.

Honestly, the small hassle is not worth either paying money for a new system or moving the existing the paddlewheel. However, it would be really nice if I could just plug in the speed and go. We have DBW, I would like it very much if the computer could just do the math for me. 8p We'll see what the reviews on the ZeroOff look like for my next boat. ;)

bigmac
03-17-2007, 01:06 PM
Well, sometimes we get glass, just don't tell anybody. :D

Probably our biggest variables are number of people and speed. We might have anywhere from 3 to 8 people (and their gear) and speeds might vary from around 19 to over 26. Depends who we're riding with that day. Once you get a base dialed in on the first ride, it's pretty simple, but I always have to play with it for that first pull or two.

Honestly, the small hassle is not worth either paying money for a new system or moving the existing the paddlewheel. However, it would be really nice if I could just plug in the speed and go. We have DBW, I would like it very much if the computer could just do the math for me. 8p We'll see what the reviews on the ZeroOff look like for my next boat. ;)

Yeh, in RPM mode that's true. It's why I prefer wakeboard mode, when it works. Zero Off would also have the advantage of being speed-settable for any speed, including for slalom at 32-34-36 mph, as opposed to Perfect Pass in which speed mode from the paddlewheel is only accurate up to about 25 mph...then it's all RPM-based.

What would be cool would be an attachment where one could just plug the USB port of their hand-held GPS into their DBW system and use that to maintain accurate speed without relying on the paddlewheel or RPMs.

MYMC
03-19-2007, 10:46 AM
As to WAAS accuracy:

Accuracy
The WAAS specification requires it to provide a position accuracy of 7.6 meters or better (for both lateral and vertical measurements), at least 95% of the time. Actual performance measurements of system at specific locations have shown it typically provides better than 1.0 meters laterally and 1.5 meters vertically throughout most of the contiguous United States and large parts of Canada and Alaska.[2] With these results, WAAS is capable of achieving the required Category I precision approach accuracy of 16 m laterally and 4.0 m vertically.

What the NTSB found:

Measured 0.9 meters / 1.3 meters The actual measured accuracy of the system (excluding receiver errors), based on the NSTB's findings.

And lastly:
Drawbacks and Limitations

For all its benefits, WAAS is not without drawbacks and critical limitations.

The broadcasting satellites are geostationary, which causes them to be less than 10 above the horizon for locations north of 71.4 latitude. This means aircraft in areas of Alaska or northern Canada may have difficulty maintaining a lock on the WAAS signal.[13]

To calculate an ionospheric grid point's delay, that point must be located between a satellite and a reference station. The low number of satellites and ground stations limit the number of points which can be calculated. This ultimately limits the operational area and accuracy due to undersampling.[citation needed]

Aircraft conducting WAAS approaches must possess certified receivers, which are much more expensive than commercial units. Garmin's least expensive receiver, the GNS 430W, has a suggested retail price of US$10,750.[14]

WAAS is not capable of the accuracies required for Category II or III ILS approaches. Thus, WAAS is not a sole-solution and either existing ILS equipment must be maintained or it must be replaced by new systems, such as the Local Area Augmentation System (LAAS).[15]
WAAS LPV approaches with 200 foot minimums can not be used at airports without medium intensity lighting, runway markings and a parallel taxiway. Smaller airports may not have these, and therefore require pilots to use higher minimums or pay to upgrade the airport.[16]

The 2004 baseline estimates the final program cost to the US Federal government as over US$3.3 billion when delivered in 2013; more than 3.7 times the original budget and 12 years behind schedule.[17]

JohnnyB
03-19-2007, 07:44 PM
As to WAAS accuracy:

Accuracy
The WAAS specification requires it to provide a position accuracy of 7.6 meters or better (for both lateral and vertical measurements), at least 95% of the time. Actual performance measurements of system at specific locations have shown it typically provides better than 1.0 meters laterally and 1.5 meters vertically throughout most of the contiguous United States and large parts of Canada and Alaska.[2] With these results, WAAS is capable of achieving the required Category I precision approach accuracy of 16 m laterally and 4.0 m vertically.

What the NTSB found:

Measured 0.9 meters / 1.3 meters The actual measured accuracy of the system (excluding receiver errors), based on the NSTB's findings.

And lastly:
Drawbacks and Limitations

For all its benefits, WAAS is not without drawbacks and critical limitations.

The broadcasting satellites are geostationary, which causes them to be less than 10 above the horizon for locations north of 71.4 latitude. This means aircraft in areas of Alaska or northern Canada may have difficulty maintaining a lock on the WAAS signal.[13]

To calculate an ionospheric grid point's delay, that point must be located between a satellite and a reference station. The low number of satellites and ground stations limit the number of points which can be calculated. This ultimately limits the operational area and accuracy due to undersampling.[citation needed]

Aircraft conducting WAAS approaches must possess certified receivers, which are much more expensive than commercial units. Garmin's least expensive receiver, the GNS 430W, has a suggested retail price of US$10,750.[14]

WAAS is not capable of the accuracies required for Category II or III ILS approaches. Thus, WAAS is not a sole-solution and either existing ILS equipment must be maintained or it must be replaced by new systems, such as the Local Area Augmentation System (LAAS).[15]
WAAS LPV approaches with 200 foot minimums can not be used at airports without medium intensity lighting, runway markings and a parallel taxiway. Smaller airports may not have these, and therefore require pilots to use higher minimums or pay to upgrade the airport.[16]

The 2004 baseline estimates the final program cost to the US Federal government as over US$3.3 billion when delivered in 2013; more than 3.7 times the original budget and 12 years behind schedule.[17]

I'm on vacation and several beers down...please summarize in very simple english :D

Ric
03-19-2007, 07:57 PM
I'm on vacation and several beers down...please summarize in very simple english :D LOOKS LIKE SOME AVIATION STUFF TO ME UH HAND ME ONE OF THOSE BEERS!

M-Funf
03-19-2007, 08:09 PM
Position isn't really too imporant when running a course, right? What's most important is SOG (speed over ground), right?

GPS position with a moving target (receiver) is not extremely accurate, even with SA (selective availability) turned off, unless you have a DGPS (differential GPS) receiver at a fixed location (like on the shore) that has an extremely accurate position. That would be easy to set up for a tournament, but not easy (or cheap) for the recreational boater

But, if I remember correctly, GPS units measuring speed is extremely accurate.

MYMC
03-19-2007, 08:30 PM
I'm on vacation and several beers down...please summarize in very simple english :D
I wouldn't run out and buy it just yet.

A meter is 3.281 feet so at best this system is off by 2.853 feet and most of the time at worst it is off by 4.265...and that is not counting reciever errors. Based on the price of the unit I would doubt that it would be as accurate as a Garmin 430 (GA aviation GPS)...so the potential for error only grows larger. Based on what I have read and heard the system is going to use the gates as way points...here is the first place for error since they have to be entered manually (the system doesn't use magnets).

Next, the boat is trying to run a "speed" not a time...this should make the system feel more like a human driver; however, the more you slow the boat down when you load it the greater the system will compensate to get the average speed it needs to complete the pass...i.e. bigger guys have the potential for getting that freight train feeling towards the end of the course when you want it least. Further this would be a decided disadvantge for LFF skiers since they will have their best turns on the 1, 3 & 5 side...leaving the boat to catch up as you attempt to make 6 ball.

Lastly, USA WaterSki is talking about tightening tolerances...I believe the proposal for 34.2 would an ideal of 16.95 with only +/- .07 deviation. So...1 mph = 5280 ft/hr /3600 sec/hr = 1.47 ft/sec. So: 34.2 mph = 50.27/sec so the system could be off by more than the deviation at any given time.

I think one day this may be the way to go...but I wouldn't be first. Just my :twocents:

WTRSK1R
03-19-2007, 08:32 PM
Maybe I am just lucky, but I have never had any issue with PP hunting around. I calibrate it on a course, and then use it both on the course and free skiing. The only frustration I have at all with it is a little bit of overshoot as you come up to speed. Other then that, as far as I can tell driving or skiing it holds speed great. Maybe it has more to do with Slalom speeds compared to Wakeboard or foiling speed. I can say is all I ever do is pick a speed, enter the crew weight and we are ready to go.

MYMC
03-19-2007, 08:38 PM
Position isn't really too imporant when running a course, right? What's most important is SOG (speed over ground), right?

GPS position with a moving target (receiver) is not extremely accurate, even with SA (selective availability) turned off, unless you have a DGPS (differential GPS) receiver at a fixed location (like on the shore) that has an extremely accurate position. That would be easy to set up for a tournament, but not easy (or cheap) for the recreational boater

But, if I remember correctly, GPS units measuring speed is extremely accurate.
A slalom run is judged on time...here is the all bouy timing table for 34.2
Fast 1.73 4.37 7.03 9.69 12.35 15.02 16.78
Ideal 1.77 4.45 7.13 9.82 12.50 15.19 16.95
Slow 1.80 4.51 7.23 9.93 12.64 15.34 17.12

Position goes back to marking your "way points" since speed is time over distance if the distance is incorrect the speed to cover that will be wrong as well.

M-Funf
03-19-2007, 08:45 PM
A slalom run is judged on time...here is the all bouy timing table for 34.2
Fast 1.73 4.37 7.03 9.69 12.35 15.02 16.78
Ideal 1.77 4.45 7.13 9.82 12.50 15.19 16.95
Slow 1.80 4.51 7.23 9.93 12.64 15.34 17.12

Got it. Thanks.

Farmer Ted
03-19-2007, 08:53 PM
I heard there's a Hybrid laser ring gyro embedded GPS cruise control being developed at a super secret "location" in Nevada that doesn't really exist *wink* *wink*

there's also a deluxe version that will include celestial navigation for those who demand the utmost from their slalom course nav aids......

projectely4
03-19-2007, 10:14 PM
i tested this system in a wakeboard boat with over 3000 lbs of weight and the system held speed perfectly, even when the rider was cutting out and against the boat. the best part was the system was extremely easy to use and didn't trequire any adjusting of settings.

MYMC
03-20-2007, 11:23 AM
i tested this system in a wakeboard boat with over 3000 lbs of weight and the system held speed perfectly, even when the rider was cutting out and against the boat. the best part was the system was extremely easy to use and didn't trequire any adjusting of settings.
Not sure how that is really different from Perfect Pass...Maeghan's X-Star has 3000lbs of ballast on top of the stock system, and Perfect Pass holds speed, is easy to use (rider name menu, on/off switch) and requires no adjustment once the system is set up to the boat/engine combo.

I think the real questions here surround the systems use in slalom where there are tolerances that must be operated within.

DooSPX
03-20-2007, 11:27 AM
I would be interested in it after the slalom part of the system is tested and proven. and when the get a retro fit kit for carb boats

Ric
03-20-2007, 11:30 AM
I heard there's a Hybrid laser ring gyro embedded GPS cruise control being developed at a super secret "location" in Nevada that doesn't really exist *wink* *wink*

there's also a deluxe version that will include celestial navigation for those who demand the utmost from their slalom course nav aids...... my slalom course is surrounded by large shade trees

WakeSeeky
03-20-2007, 12:17 PM
Just to be clear, once we have PerfectPass dialed in it holds speed (haha) perfectly. My complaint, and it's a very minor one, is that we have to figure out how RPM translates to speed every time we change it. If weight/speed/water conditions were the same or similar all the time, this wouldn't be an issue at all. In real life, though, conditions vary quite a bit for us. I would just like it if I could put in a speed without trying to guesstimate the correct RPM setting.

I'm not unhappy with PerfectPass, it works great once it's set and any competitor is going to have a hard time matching their customer service. I'm also not looking to spend a bunch of money just to solve what is really a minor irritation to me.

bigmac
03-20-2007, 12:24 PM
Just to be clear, once we have PerfectPass dialed in it holds speed (haha) perfectly. My complaint, and it's a very minor one, is that we have to figure out how RPM translates to speed every time we change it. If weight/speed/water conditions were the same or similar all the time, this wouldn't be an issue at all. In real life, though, conditions vary quite a bit for us. I would just like it if I could put in a speed without trying to guesstimate the correct RPM setting.

I'm not unhappy with PerfectPass, it works great once it's set and any competitor is going to have a hard time matching their customer service. I'm also not looking to spend a bunch of money just to solve what is really a minor irritation to me.That's the problem with RPM mode - the speed varies from load to load, skier to skier. It's the reason I have persisted in trying to make Wakeboard mode optimally usable.

WakeSeeky
03-20-2007, 12:32 PM
That's the problem with RPM mode - the speed varies from load to load, skier to skier. It's the reason I have persisted in trying to make Wakeboard mode optimally usable.

Exactly. We've discussed moving the paddle wheel, but I don't know if that would completely solve the problem for us. We do ride in pretty rough water sometimes. The nice thing about RPM is that it holds speed no matter what the conditions are like. Although I'm sure moving the paddle wheel would help, I'm not convinced it would work well enough for us to justify the hassle.

bigmac
03-20-2007, 01:10 PM
Exactly. We've discussed moving the paddle wheel, but I don't know if that would completely solve the problem for us. We do ride in pretty rough water sometimes. The nice thing about RPM is that it holds speed no matter what the conditions are like. Although I'm sure moving the paddle wheel would help, I'm not convinced it would work well enough for us to justify the hassle.


Or...I've read that there is a new speed control out there that uses GPS to measure the speed instead of the paddlewheel. THAT would eliminate the whole problem....

...oh, wait....

WakeSeeky
03-20-2007, 06:45 PM
Or...I've read that there is a new speed control out there that uses GPS to measure the speed instead of the paddlewheel. THAT would eliminate the whole problem....

...oh, wait....

:D

Does it work?

puck_11
03-22-2007, 04:17 PM
I e-mailed this company about a week ago with a few questions trying to get some information, because their website sucks. Still haven't heard a word.

bigmac
03-22-2007, 05:08 PM
I e-mailed this company about a week ago with a few questions trying to get some information, because their website sucks. Still haven't heard a word.From other web sites I've read, people are having more success with the telephone.

FrankSchwab
03-23-2007, 01:36 AM
The problem with measuring either the paddlewheel, engine rpm, or GPS is that each has their own serious limitations. Paddlewheels change measurement depending on boat weight and left/right loading. Engine RPM changes with the same variables. GPS is insensitive to these and can calculate steady-state velocity very accurately, but has very slow update rates (1/sec), and tends to have internal software filtering that slows its response even more.

The ideal cruise control would use something like the paddlewheel or engine RPM because of their fast update speed (100 /sec), and use the GPS to CALIBRATE this unreliable input. I'm amazed that something like PP doesn't have a GPS input to eliminate almost all calibration requirements, or that the ZeroOff doesn't have a speedo input (paddlewheel) or Tach input to provide additional information to maximize its accuracy.

/frank

Ric
03-23-2007, 11:26 AM
we were on the bridge of a slow movin hundred footer a few weeks back cruising the bay at night. Capt. had alotta information at hand, gps, radar and a mapping screen(based on gps)

radar would show blips of the channel markers which an old salt could differentiate from blips of error.

these would show the ship on course, and yet the gps mapping showed the boat off course by 10 or 20ftI cannot say which was incorrect except every now and then we could see the markers visibly and appeared we were on course when the gps map would say differently.

maybe it was an acceptable error, or maybe it was old software but it was the first thing to cross my mind when I read this thread and thought about SLALOM!