FAQs - Sure-Path GPS Boat Lane Tracking

A Base station can provide RTK error data to any number of Rovers concurrently. Therefore additional boats just need their own Rover setup to work. A Rover setup consists of an antenna, receiver and phone (unfortunately the expensive bits).

There is one limitation however, Rovers should be within 10km (6 miles) of the Base. Beyond that, the system works but accuracy starts to degrade.

Yes, when mapping the course, mark the buoys G1 to G4 as per the diagram below. This gives a "short" course length of 177m. However, in each direction, Sure-Path only needs a start point (the centre point of the entrance gates) and a bearing to be able to create the centre line of the course and hence to calculate deviations from that centre line. Thus the mapped length of the course is irrelevant.

Note that if you are surveying for homologation in preparation for R or L class tournament, then the courses in each direction should be surveyed separately and homologated as separate items.

As per the World Rules, when displaying deviations at each buoy, Sure-Path uses the convention that a deviation towards the skier is positive and a deviation away from the skier is negative. Thus at buoy 1, a positive deviation is to the right of centre; at buoy 2, a positive deviation is to the left of centre...etc. This convention is based on the assumption that being towards the skier is an advantage and away from the skier is a disadvantage.

Although not specified (or even required) in the Rules, Sure-Path applies the same convention to the pregates and gates. Therefore a positive deviation is left of centre and negative is to the right of centre.

The 2024 Rule Book changed the X/Y referencing for Jump homologation and boat path calculation. The X Axis is defined by a line drawn between ST15 and MT15. The Y Axis is a line perpendicular to the X Axis and passing through the MT15 buoy.

Therefore, for boat path purposes, only the ST15 and MT15 buoys need to be mapped. The boat path is a line drawn parallel to the X Axis, 2 metres further away from the jump ramp.

Given that the boat path reference does not use the 19 metre buoys, it is important that the 19s are placed as close as possible to 4 metres from the corresponding 15s. The Rule Book Homologation Guidelines specify that the 19s should be visually straight and no more than +/- 4cm from the 4 metre width with their corresponding 15s.

If setting out a jump course from scratch (performing a so called "stakeout"), Sure-Path only requires either the ST15 or ST19 as a start point together with a "direction" point to create a virtual course to which all other buoys are compared.

The Buoy Check button will measure the current position of a buoy and display how far off it is from when it was originally mapped. It does not change the existing mapping. If the buoy has not been previously mapped, the Buoy Check button will not be enabled.

This is different to the offset shown on the circular grid display which always shows how far off a buoy is from its "ideal" position based on a course derived from the course reference line. In the case of slalom, the reference centre line is derived from the centre points of the entrance and exit gates (ie buoys G1 to G4). In the case of Jump, the reference line is drawn from the ST15 buoy to the MT15 buoy.

Buoy Check was originally designed to be a quick test to see if a floating course had moved since its original mapping. Since that time it has also proved to be very useful whilst in Stakeout Mode.

Note: In Stakeout Mode, all buoy positions are pre-populated with ideal coordinates as if they had been mapped in the usual way. Therefore whilst in Stakeout Mode, the Buoy Check offsets will be the same as the offsets shown on the circular grid. Once you have left Stakeout Mode and have done a real mapping of a buoy, Buoy Check only gives the offset from the last mapping and will almost certainly not be exactly the same as the circular grid offset (which is still showing the offset from "ideal").