What is Zero Off?
Zero Off is the leading innovative GPS speed control for boats.

How does Zero Off work (Simplified)?
The ZeroOff system uses input from satellites and the engine management system to provide an accurate and consistent speed control and timing. No more need for timing boxes, slalom switches or magnets! ZeroOff is based solely on the speed across the surface of the water so there is no requirement for skier weight, crew weight, or even any kind of wind adjustment. You simply set the desired speed and go.

How does Zero Off work (Technical)?

Zero Off provides true closed loop control of boat speed which means that, as long as the boat motor has enough power, the boat will accurately track the speed desired by the driver without any need for complicated setup information to be entered into the system. Simply pick your desired speed, and shove the throttle handle wide open. ZeroOff will take care of the rest. Closed loop speed feedback is based on signals received from the worldwide GPS satellite system put in place by the US government. For this reason, there is no need for maintenance intensive and unreliable pilot tubes or paddle wheels to provide a speed measurement. As long as the GPS antenna can see the sky, the ZeroOff is good to go with speeds controlled to within 0.1mph at all times… no calibration or setup procedures required. Using GPS also allows ZeroOff to take advantage of position information provided by the satellite signals. ZeroOff can use GPS data to identify a boat’s location on the surface of the earth with sufficient accuracy that courses for sports such as Slalom and Jump competitions can be mapped and memorized.

How accurate is Zero Off?

ZeroOff has been certified by the American Water Ski Association for use in all levels of Slalom, Jump and Trick competitions without the need for course magnets, and has shown itself to consistently control times in Slalom competitions to within +/- 1 hundredth of a second, regardless of adverse weather or course conditions, or skier variability. While position accuracy derived from GPS satellite data is not as highly accurate as speed data, Zero Off uses special algorithms and techniques to estimate position with sufficient accuracy and update rate to allow consistent course timing to be achieved, as demonstrated over the course of many thousands of passes through the course during development and field experience.

Does Zero Off work in cloud cover?

ZeroOff has been tested in heavy cloud cover in several segments of the USA and UK and has not shown any major decline in GPS signal strength that would effect speed or timing accuracy. FACT: In June 2007 Zero Off pulled a near perfect slalom event in with gusts of 30+ mph, over 1/4 mile thick cloud cover during tropical storm Barry.

 

Why Choose Zero Off (3 Event)?
Competitive skiers like it because it levels the playing field and ensures consistent fair pulls through the course, while ski schools like it’s ease of use in dealing with a wide range of skier styles and skill levels. No more entering skier and crew weights, or adjusting for head/tail winds or currents! ZeroOff provides a feel reminiscent of the expert hand drivers from the era before automatic speed control systems became available. Because it is a closed loop system, ZeroOff responds to how the skier pulls on the boat, and allows he or she to get free of the boat at appropriate times as they pass through the course. ZeroOff developers have worked closely with leading athletes from the world of three event skiing to ensure that not only is speed and course timing controlled accurately, but that the “feel” of the pull is outstanding and in synch with the skier’s needs while passing down the course. All the driver has to focus on is maintaining his boat path.

Why Choose Zero Off (Wakeboard & Trick)?
Zero Off locks in on the target speed quickly and reliably with minimal overshoot, and handles turns without sagging or overshooting excessively. This makes it very well suited for use in sports such as Wakeboarding and Trick skiing. Wakeboarders will love how it handles double-ups. Drivers can quit worrying about what the speed is and focus completely on steering the boat.

How easy is it to install?
Simple! 5 wires which include; battery power, ignition, ground, Can(+),Can(-) and an antenna.

Is there any calibration required?
NO! There is no requirement for skier weight, crew weight, or even any kind of wind adjustment.

How do I handle tight turns for 3-Event skiers?
Simply pull back on the throttle lever as required while making tight turns to allow speed to droop in tight turns, or, if holding set speed through the turn is acceptable, simply let Zero Off maintain the speed. If the turn is tight, this will result in a very audible engine response which drivers may not be used to as power is applied to hold the speed. When the turn is done, open the throttle back up to resume accurate speed control.

Does it fit on my boat?
Currently the Zero Off speed control system only works on 2006-2008 boats with a drive-by-wire, GM 5.7L & 6.0L engines that use an eControls ECU. These retrofit kits that will be available on the following schedules:

1. 2007 model year Correct Craft Boats Zero Off kits - Available 11/1/07
2. 2006 model year Correct Craft Boats Zero Off kits - Available 1/1/08
3. 2008 model year MasterCraft /Malibu/Skiers Choice Boats Zero Off kits - Available 1/1/08
4. 2006 model year MasterCraft /Malibu/Skiers Choice Boats Zero Off kits - Available 2/1/08
5. 2007 model year MasterCraft /Malibu/Skiers Choice Boats Zero Off kits - Available 1 /1/08