Tom351

I think dealing with slack would be a huge issue behind a (theoretical) constant-speed boat. My reasoning is that a traditional boat is able to run up the speed a bit when the line load is decreased from skier edge change into the buoy (especially if running ZeroOff "A"). This slight overspeed helps to reduce or eliminate slack for the skier. So not only would a skier behind a truly constant-speed boat likely have more potential for slack thru the turn, but the hit from any slack in the line would be much harder if the boat is not going to lose any speed at all- compared to the current reality where the boat takes at least part of the hit and slows down- and makes up for it more gradually (depending on speed control setting, but there is at least some latency with any setting).

I was curious what speed you get from that boat at "full noise" (with Joel freaking Howley pulling on it)....gate to gate times from looking at the video frames are around 17.2s- so probably about 33.7mph

Looks like the ski came around and onto (instead of under) the rope....I always wondered how that would go down if it happened....now I know

@skihart https://goo.gl/maps/nSDPfeWw8nK2

I agree on the 3M Eraser Wheel- used in on my hull when removing a pinstripe. No hull damage- also, plastic razor blades work well....as do metal razor blades, but with much higher stakes if you slip.

The hard part for dropping in actual gates would be triggering the Offcourse unit at the right point relative to the gate. If Offcourse fires in a "zero" ball as @Horton mentioned (which would make sense) then the driver would have a hard time triggering at the correct point relative to the gate. Or maybe the Offcourse trigger/timing is relative to actual gate location- in which case the driver could trigger the system as he drives past the actual gate buoy(s)....or if skiing without gates the driver would trigger around the time the skier turns in. Although, the website says that the unit holds 24 balls- for 4 passes. So using a zero ball and 7 per pass would not be the best use of the mag capacity. It would be a fun/friendly contest to see who can get the most "buoys" at a given speed/length where 6 is normal, but 8 or 10 or 12 buoys start to get really tough.

Denatured alcohol works really well also.

https://www.instagram.com/p/BoZHHt4AVRm/?utm_source=ig_share_sheet&igshid=1slpccvm5xn29

@andjules I was thinking the same thing- and that it may help him to ski opposite (to keep things more separate and prevent cross contamination) but any wakeboarder at that level rides so much switch that I would imagine is "switch" wakeboarding is still better than 99.9% of other wakeboarders riding normal.

Great point by @BoneHead - and on top of this, the latest ZO systems use dual receivers- which I would imagine only increases the overall accuracy beyond the published spec of either receiver used individually (not that location accuracy is all that important in a speed control system anyway)

One other thought: 3 meters seems like a fairly large tolerance for location, but the GPS receiver spec sheet lists the speed accuracy at 0.1 knot. So while you might not want to place buoys based on GPS readings, it's accuracy for determining moving speed seems pretty good. I assume this is because it takes 5 readings per second, and the 3m margin of error gets quickly averaged out across the multiple readings and the speed calculation derived from them.

I think this is the GPS receiver that both PP and ZO use: https://static.garmincdn.com/pumac/GPS_18x_Tech_Specs.pdf Accuracy info is on page10 Not sure if it uses GPS or WAAS though.

For GPS I map a line right down the mainline (you may be doing this already). Some other skiers just go to a point and search radially, but if you map the mainline then you can start deliberately on one side of the mainline and then just move cross-course until you snag it- seems way faster than going to a point and trying to search in circles from there. A good idea that another skier had was to fill a couple of jugs approx 80% with water and sink them on the same section of mainline- this lifts the mainline off of the bottom in that section and makes it easier to snag.

Here is a sample of video from a Hero6 mounted on a SkiDoc pylon mount. Was shot in 1080P/narrow FOV (GoPro calls it "linear" mode)/ at 120FPS with a little bit of zoom. I used to shoot 4k or 2.7k and zoom in later when shooting from the boat, but if you drop the resolution on the GoPro you can increase the framerate for Slo-Mo (I slowed it to 1/4 speed at 3 ball in the clip below). The video is not that great and a phone or real camera with narrower lens would be better for sure. The GPS feature is nice though on the Hero5 and up (if you can get the overlay software to work). With pylon mount you can see the boat speed variation for the run overlayed on the video: https://www.dropbox.com/s/1k7yy2m4tex2m7z/Hero6-1080.mp4?dl=0 or you can chest or helmet mount to get skier telemetry: (shot in 2.7k/superview/60fps) https://www.dropbox.com/s/k39xfrsy5i5pml5/32_15T.mp4?dl=0

You can see the entire fall in this clip..she took a huge slack hit at the very end:

@6balls I don't think PP (stargazer) will run faster in that case (unless you are running magnets). As I understand it: it uses your mapped GPS gate location to trigger the timer, and the rest of the points are just based on distance traveled (with PP assuming each buoy is at the correct distance) PP has no way to know that your course is long or short (assuming that I am correct). The two gate mappings are independent so they are used only as an entrance gate while ignoring the exit. This would make using the system in an 8 buoy course setup possible. Someone please correct me if I am wrong.

@DangerBoy yes, the deep V handle is great for someone learning to deep water start...or for people that are rusty at it. Not only does keep the ski centered, but it seems to make people realize that they need to be a bit forward and "ride" the ski up instead of leaning back and fighting...maybe because it makes them feel like the rope will keep the ski tip up for them- and they dont try to keep the ski at a super steep angle like many people often do right before they pop the handle.

http://www.perfski.com/ski/ropes-and-handles/slalom-handles/ho-2017-15-elite-deep-v-handle10.html

With modern DBW throttle it would probably be a simple software change for the manufacturer to prevent adding throttle in reverse while moving forward at skiing speed. I am not sure if the transmission engagement is still mechanical or not (at the lever), but if on a sensor then reverse could be locked out as well at higher forward speeds.

I guess he slammed it in reverse when he realized that he was driving over the buoys- probably thought he was pulling it to idle.

Also, the motor blowing up or seizing does not explain the boat path before the dive- unless there were such crazy sounds coming from the engine that the driver was looking elsewhere.

reminds me of this one: (I think I first saw this here at BOS...years ago)

@DangerBoy - I got on mine yesterday- It skied great! I switched from a 2010 S1 and the transition was easy (took a handful of open water pulls then straight into the course)...and the ski is clearly a huge upgrade! Thanks for posting the sale info!

No problem @MC351stars - I had been meaning to try to sell that old module but had been lazy... Thanks for making it easy!