Zero Off remapping

[Zman]

Every so often we will find that ZO beeps a little ahead of the boat guides in one direction, a little behind going the other direction.

A couple questions.

1) What will this impact, if anything?

2) How much of this difference would you allow before remapping?

[DW]

@Zman : GPS satellites drift so your mapping will also drift over time.

1. For us, it impacted the green balls and gate entry at least that is what we think and felt. Since ZO doesn't actually run a steady speed but enters the course a bit fast, it makes a difference. We were surprised at the difference when we remapped, which in our case evened out the speed trace from green balls to entry gates. I think the speed trace asymmetry it creates when the mapping is off accounts for the difficulty we felt running the course since it pretty much impacts the start of your pass (either way).

2. Very little and as noted by @Horton in the other ZO thread, 90 days seems like a logical time window to remap a course. Ours seemed to be 10-15' off IIRC.

[Horton]

 

[mbabiash]

Solar flares. Remap on a different day.

[Kelvin]

The World guidelines of remapping each day are extreme, but are designed to work all over the world. In some parts of the world, GPS satellite reception is not nearly as good as the US and more drift can occur. I do pay more attention to the beeps now after reading threads like this.