Is there a Zero Off Easter egg?

[Ralph Lee]

That engine sounds right to me!

[dbutcher]

The engine sound makes sense. Trickers need constant speed with instant return to set speed without overspeeding when a trick slows the boat.

[Horton]

The engine sound from 2 to 3 gets my attention. Sounds like more of a spike than normal.

[Roger]

I timed it several times to get an average and it looks legit.

[DanE]

Maybe the new Gopro quick desktop app could reveal the difference between trick and slalom mode with the Hero5 mounted to the boat? It shows a speed and g force overlay collected from the gps data in the camera.

[bassfooter]

@Horton @Gloersen Would a higher elevation make the engine spike higher than usual? I think this site sits fairly high (Salt Lake airport is just over 4,000').

 

[Horton]

@DanE sadly the GoPro data is far too inadequate. Will Bush has some professional GPS equipment and i imagine he will do some real analysis.

[Horton]

@bassfooter mmmmm maybe but the Yeti is not the only person to experience this. The idea comes from Orlando skiers.

[Horton]

Note .... trick mode ABC may not be exactly what we expect from slalom ABC. IDK

[DanE]

@Horton How so? Sample rate? Resolution?

[Horton]

@DanE from what I have experienced working with the Trace hardware is that consumer action cam and similar GPS / accelerometer tools are insufficient. Not only do I doubt the basic data quality but I also suspect that the way the data is output will not match what you would need to learn something meaningful. I have spent WAY TOO many hours working with the Trace data and personally doubt the GoPro data is an order of magnitude better.

 

I looked at some GoPro5 video that Travis Fisher put on Facebook and at first glance it does not look right. I would like to get a raw video file and look closer.

 

Bottom line is you need Pro quality GPS / Accelerometer hardware and software to really analyze ZO or a skier. You can buy a $200 GoPro and it will be fun but I seriously doubt that you will learn a lot from it.

 

On the other hand if you do make the investment and it works I would be thrilled to see it.

[Gloersen]

The audio in that clip sure sounds (unequivocally) like a greater RPM spread running slalom in trick mode vs slalom mode. It’s reasonable to assume that the boat’s delta Velocity is notably greater from gate to gate during that slalom pass in trick mode.

 

Remember when PP came on the scene, the powers that be advocated a more constant boat velocity during the pass. Then along comes ZO using GPS velocity to determine baseline speeds but added (on top of velocimetry alone) super sensitive accelerometer data acquisition (1-2-3 settings) to modulate throttle activation (A-B-C settings); the relative steady velocity of the boat became even greater. IMO this has been to the detriment of stronger (not so “light on the line”), heavier, big-turn type skiers, etc.

 

If the ABT’s are in tolerance, and if trick ski mode slalom is mainly velocimeter data based speed control, and certain skier technique can harness a greater swing effect; who cares if the boat path's oscillatory speed over ground has a greater delta from gate to gate?

 

An option that provides a skier a purely (or closely) velocimeter based only (no g’s clipping values) throttle correction would be cool!

 

Not holding my breath, but hopefully Parsons, Bush, et.al. can come up with another option to ZO that many skiers would appreciate.

 

[Horton]

Ok @Gloersen you have to use some smaller words for folks like me from "the land of the tiny brains".... Remember I was once a jumper. "Velocimetry" really? I had to google it make sure you were not making up words. :- )

 

Ok seriously - if the RPMs are limited in slalom mode but are not (or less) limited in trick mode => in Trick mode the boat can give more of a burst of gas when the skier pulls. Right? I would think the boat speed would actually be more constant. In slalom mode If a heavy skier pulls to long or too hard the ZO is making up time when the skier is not pulling. In trick mode the ZO is getting it done when the skier is on the line. Sounds pretty good to me.

 

By the way, anyone notice Yeti crushing 39 in sub 60 degree water in November? Dude is WAY underrated as a skier

 

 

[Gloersen]

@Horton - well, "velocimetry" is a lot easier to understand than "accelerometry" imho.

 

we should run some passes in both modes with video of the dashboard showing the buoy to buoy RPM spread during the pass. The RPM spread is typically linear to the velocity spread.

 

too bad the water is so dang cold now; hard to get motivated with video equipment.

[ozski]

Sounds just like perfect pass with a switch... hmmmm

[Ralph Lee]

I'm always hoping to see a thread about a new version of Zero Off. This is the first sliver of hope I've seen. It's hard to argue with results, but for me Zero off is nightmarish compared to PP with the switch.

[MISkier]

If the ABT times are good, then Trick settings of A, B, C should be considered to be Slalom settings of D, E, F. No numbers, just the 3 letter settings. However, I would be skeptical that the ABT are really within tight tolerance.

[ozski]

I grew up skiing with both hand and foot drivers, there are times when I think we are getting a little too precious.

[Horton]

@ozski are you ready to go back to setting your fin with a pencil and a ruler?

[ozski]

@Horton In skiing terms I'm not in the 1% that would be the ones that might take a benefit out of this. I'm squarely in the 99% that is better off focused on technical improvements to my skiing. I'm not against innovation either, I own and run a tech company. For the last three years I've been reading about how you need to own a ZO boat because its so good. I'm yet to get what I consider a junky pull out of my ZO 6.0 either. There are tons of skiers out there running long line at 32 - 34mph that should never put there head in this space. I have nothing against the conversation or moving forward, mine was just an observation because I don't want think I ever want to hear a novice start to question the pull from ZO. As you said its not just a few people that read this site. Its just a few that bother to comment.

[Milford]

Nick is always playing with ideas and constantly trying new things to improve the sport. I have skied Trick mode now 4 sets and have to admit, I prefer it. I originally had the attitude of "why even try, it's not available in a tournament", but Nick convinced me to give it a shot in the spirit of trying to improve the sport. Glad I did and hope that he can make headway with the powers that be to have something like this as an option in the near future. Really love the way it applies power when you engage the boat and then immediately shuts down at the edge change.

 

 

[Horton]

@ozski I 100% agree that skiers misplace their focus away from technique all the time. Obsessing about fin settings and ZO before they have the core skills. Skiers SUCK at prioritization

 

As the rope gets shorter and skills increase so does the need for better skis, settings and everything else.

 

You ski behind a 6L 196. That is one of the best options possible and I would assume your boat has a great pull. If you ski behind enough different boats you are going to find at least a few VERY expensive boats that ski like crap or that take a lot of rides to adjust to. If trick mode is better than standard boats especially for guys like me that are a bit heavy on the line....

 

Ok seriously i lost track of my point --- just not sure why you are going negative about people thinking out of the box. Thinking about taking about water skiing IS the point of this web site.

[Horton]

@Milford that sounds SOOOOO good. Did you happen to be around last year when Yeti was playing with 5 and 6 blade props?

[BG1]

The boat in Nick’s video sounds a lot like what Zero Off slalom mode originally sounded like to me before people complained and they started trying to “calm it down” or whatever. I liked the original a lot but never liked it once they added the 1-2-3 settings. Never really could get the boat off me. Wouldn’t it be wild if it goes full circle and they add a ZOO (Zero Off Original) setting? They already have the software and programing. I'm convinced I would use it. Maybe now that most skiers technique has evolved to work with the current version of Zero Off some are ready to tame the ZOO “beast” and ride it to a PB.

[Horton]

Listen to the difference!

 

Yeti 38 off Slalom Mode C2

https://youtu.be/-D4orm1gQEw

 

Trick Mode 39 off 36 MPH in a dry suit

https://youtu.be/l-XcojcZ3EU

[ToddL]

@Horton "skiers misplace their focus away from technique all the time. Obsessing about fin settings and ZO before they have the core skills... As the rope gets shorter and skills increase so does the need for better skis, settings and everything else. "

 

So true. Additionally, someone very smart once said, "Indian shoots better with the straightest arrow." If all skiers will benefit from a better speed control pull, then all skiers should be excited about the possibility.

[ktm300]

@BG1 Agreed. My first go with ZO was in an 08 MC TT. That boat roared. My first few times down the course pulling a skier, I thought that there was no way that could be right. Major rpm swings (made obvious by the Johnny Cash MC). However, it felt fine skiing behind it. Would be funny if after thousands of hours of conversation about ZO we ended up where we started.

[bishop8950]

I tried trick mode yesterday and it was fun. Noticeably different. I intend to chat about it with Will Bush as some point and until then I will stay out of the "how it works and why it feels different" and just comment on what I felt as a skier

 

The main thing I noticed was how free of the boat I felt. As soon as I changed edges the boat shut down and I floated up to the buoy. Then the boat waited for me to finish my turn and get under the rope before it gassed me side to side. It felt good. I think it would feel even better as it got shorter. I stayed at 32/35 because I was coming off 12 days off.

 

Playing with the settings in trick mode it seems to trend the same as slalom. I felt the boat quicker on C than A. This said I am not sure I would use the same settings in trick mode, I would need more time to tell.

 

I went back and forth from trick and slalom while staying at C1 and it felt like the boat was running on me in slalom mode and waiting for me in trick mode. It's not hard to feel the shorter and stronger shot from the boat while in trick mode. And while the boat does sound like its reving more, it never bothered me because it happened when I was ready for it.

 

I want to play with it more but there is definitely something there.

[DW]

I hope somebody can chime in or knows the specific technical differences between Trick mode and Slalom mode and is able to provide the details in addition to the skier feel differences being noted in this thread. Nice to know since Trick mode seems to be getting positive feedback.

[Gloersen]

@bishop8950 - concur with your assessment.

 

Only 28s/34 yesterday A1/B1/C1 (B1 prefered) in trick mode 2 sets, the last few passes in slalom mode.

 

But, very notable differences just as you described.

 

The first thing noticed being a more progressive gate pull and much more space in front of 1 ball, could be a slow 1B time though.

 

A few deep pulls out of the onside and the throttle was right there.

 

I doubt that type of throttle response could be based on GPS determined speed data only and retract any prior conjecture that accelerometry data is not used. It most likely is in play and am very curious as to what the "g" range is set as clipping values in trick mode.

 

My conclusion is that it felt so much different (in some ways better and overall perhaps easier on the body) that there is no point in practicing in this mode if tournament skiing is planned.

 

But it would be good if skiing pioneers progress something from this trick mode application into a viable slalom mode option(s). I would then most definitely practice in trick mode slalom... e.g., the new "Y" slalom settings.

 

 

[Horton]

The one thing that I can't stop thinking about is the possibility that slalom in trick mode will make boats with very different power plants (or props) feel less different. Maybe.... we can hope.

[dbutcher]

I have skied two short slalom sets using trick mode. One was behind a 196 with the 5.7L 343 engine (Acme 422 prop). The other was behind a 200 with a 5.7L 343 engine (Acme 654 prop). I felt no difference between the two in the pull. However, the driver told me there was significantly less RPM variation with the 200. That could be because the 200 turns more RPM's. I felt little difference with either between trick mode and slalom mode. I'm guessing that if the driver didn't tell me, I wouldn't know which mode he was in. I skied in both modes in the same set with both boats. I ski at 30.4 mph so that could be different than 34 or 36. For me personally, trick mode vs. slalom mode is a non-issue. I'm guessing that slalom mode will use less gasoline.

[BG1]

I'll gladly pay the extra 5 cents per pass:-)

[scoke]

Well I couldn't resist. At first this appeared to be an elaborate Aprils fools joke, until a couple of guys texted me saying they tested it, ok i'll bite. WOW

 

Testing was on my 2014 200 with a 5.7L 343 engine Acme 654 prop, former promo boat.

 

Typically I ski A2. We ran a full set on Slalom mode, A2 doing the usual stuff. Then at the end of the set, switched it over to Trick mode while keeping A2.

 

At 34.2, this is a huge improvement, BIG rpm swings can be heard by the passenger and the driver. Ironically, it felt like we were going 32mph or less and felt fantastic. It seemed to be a pumped up version of perfect pass. Also, my gut is, the setting does not matter or is even used at that speed but that's just conjecture. Further testing would be needed.

 

(Edit: My gut is just that regarding the settings. Some of you guys have tested settings, I personally did not but would love to try different settings. It's interesting that the rpm's and loads are very compact, stout but reactive. Which is why I would conjecture the ABC settings do not come in to play or VERY little into play.)

 

At 1 ball, the boat wasnt exactly there for me but I knew it would be behind the boat. Rest of the buoys we linked up and found a nice Rhythm.

 

 

The video doesn't lie, more importantly the Audio. If you crank up the audio and play the two one after the other, it's VERY obvious and hilarious for that matter.

 

Decent quality video shot on my iphone. If anyone wants it or could host it and run it through an audio program.

 

Without pulling the rope in short, just a big assumption, this is an improvement to Zero Off and would be the same scenario on all boats.

 

[Milford]

@scoke I agree with you and felt the same thing with regard to it feeling slow. So...we started timing each pass with an iPhone to see if it was slow. Now keep in mind, we were only looking at full pass times and not getting each buoy, but the times were within .01 of actual. Using an iPhone is not ideal, as the thumb can easily miss .02, so to really test we would need get a ZO head unit reprogrammed to time each buoy, in trick mode. I believe Nick is working on that now.

 

BTW - I matched my 5 year PB on my first set using trick mode, so I was very skeptical as to if the times were legit and to my surprise, they were. This was in 54 degree water in a dry suit. I think the shorter the line gets the more benefit this setting offers. Really starts to become noticeable between 35 through 41 with the biggest benefit at the 39-41 lengths.

 

When you listen to the video of how the boat reacts in trick mode, it just sounds right. Only applies power when needed and doesn't keep throttling after the release off the second wake. If I could choose today, this would be my setting. Really need to play with it more, but unfortunately our lakes turned solid a few weeks ago.

 

Really think Nick is on to something and is talking to the right people to explore this further.

[Edbrazil]

Interesting discussions about how different legitimate (?) passes can feel. There should

be some old Al Lockett timing boxes and magnets around somewhere, and cheap. To

verify that you are getting Kosher times, totally independent of ZO.

 

[Ralph Lee]

I'm super excited about this discussion, and loving the feedback from the skiers still on the water!!

[Edbrazil]

Note to @Mark_Matis But how do you know that the numbers that ZO gives you are

correct? I remain a bit of skeptic about their system of "Virtual Times". Seems like a bit

of Voodoo to me. I know that initially, there were comparison tests run, but does the

ZO actually always give accurate times via integrating the GPS velocities? I have done

some work with a Stalker radar/computer system, pre-ZO, and the speed variations in the

course are a lot more than a speedometer will indicate. But, I have not done any of that

research recently. Would be a fun project, though.

And, of course, the "speed over the bottom" is still a good concept. Initially, meant to

be compensating for any current at the site.

[MISkier]

@Edbrazil, my understanding is the virtual timing is just adding up the distance traveled over the elapsed clock time by using many samples of the boat speed for the duration of the samples. When the sum of the samples reaches a benchmark distance relative to a particular course segment, it records the time elapsed to that point. There are a few questions to ask:

 

1. How accurate is the clock in the ZO unit?

2. How many samples are used? That is, what is the frequency for measuring speed and over what duration is each measurement interval?

3. How accurate is the speed calculation from GPS? I did this calculation for a Garmin eTrex Legend handheld, based on the specs. For 36 mph, it indicated something like 99.68% accuracy (I think that was with WAAS). I assume the ZO unit is at least as accurate as the handheld.

4. How accurate is ZO in starting the timer at the actual gates?

 

So, ZO knows that you traveled the 259 meters in x time and it also knows the amount of time it took to cover the various gate-to-buoy and buoy-to-buoy distances.

 

I think there were some previous side-by-side tests with a PerfectPass installed in the same boat and using magnets. I think the results were that ZO was accurate.

[Roger]

@MISkier : @Edbrazil - "I think there were some previous side-by-side tests with a PerfectPass installed in the same boat and using magnets. I think the results were that ZO was accurate."

 

Yes, there were multiple tests done at multiple sites and the external timers agreed with ZO (or vice verse if you like) to within .01 at each buoy. I know that at least one test was done where PP would have been a plus 25 minus 25 to compensate for the wind and ZO was still dead on.

[scoke]

Zero off blew away Stargazer when it came to sampling, responsiveness and precision:

 

 

[MISkier]

@Roger, do you know if ZO is timing to a specific GPS position/offset or if it just calculates distance traveled by the boat and records times when the boat traverses the expected distances?

 

Just so I don't get too far off topic, i would be interested in the feedback on the trick setting option that Nick receives from whomever @Milford mentioned he would be talking to.

[Roger]

@MISkier - As I understand it, it tracks distance traveled and inserts the accumulated time for each way-point reached. GPS is VERY accurate for distance traveled, just not for absolute position on the planet.

[Than_Bogan]

I was hoping somebody else would, but no such luck, so now I'm going to be the one to ask the unpopular question:

 

Are we sure we want a ZO setting that makes short lines easier?

 

We're already in some dangerous territory where the top pros are on such a short line that the driver plays a critically important role. We may soon have to look for ways to make the sport harder.

[The_MS]

Not to be a negative nelly but ZO wont do a thing about this.

 

[Horton]

@ms you are a negative nelly.

 

It's not really up to zero off. We're not talking about a hardware change. We just need a software tweak to include times and maybe the menus. I'm sure in the end it is not as simple as I make it sound but if we all torture Will Bush enough it can happen.

[Wish]

If this turns out to be a great thing and something ZO works into their system..perfect!!. If everybody starts using it feels the advantage and sticks with it, it becomes an advantage for no one..not so perfect. How about ZO puts in a setting that feels like PP instead (or at least also). If it's great, same thing. If not, the majority of PP users would probably enjoy going to tournaments and skiing behind others ZO boats and in general this increasing the pool of skiers enjoying their system. Just sayn.....

[Horton]

@Than_Bogan What if?

 

What if it makes all boats feel more similar and maybe event more like Perfect Pass.

What if it takes some of Smith's dominance away? Nothing against Nate but it is boring seeing him win everything.

 

[Ralph Lee]

@Horton Does the decline in tournament participation coincide with implantation of Zero Off?

 

That may be a good selling point to the powers in charge.

[Bruce_Butterfield]

@Than_Bogan sorry, but you struck a nerve.

How easy or hard a pull any speed control provides is determined nearly 100% by the math coded into the control algorithm.

The fundamental argument in favor of speed control from the beginning has been "to give every skier the same pull". To date, the selected speed controls have failed miserably in this goal. The current implementation of ZO gives a MUCH harder pull to heavier or hard pulling skiers - it's the acceleration and timing that makes the pull hard, not the speed. This gives a fundamentental disadvantage to a large percentage of skiers.

Until we get to the proverbial tug boat that doesn't even notice the skier, improving the algorithms to actually get closer to goal of "same pull for all" should be fully pursued - particularly by skiers, not controls engineers who don't have a clue what goes on behind a boat.

 

<>