When you have a 1000m field, your cable length will be about that length too. Maybe a little extra, but not much. Theoretically if the wind is strong enough you can "kite" all the way up and since you're being released almost on top of the winch, you would be released at almost 1000m.
In practice, with a moderate headwind and moderate technique the average height you can reach is more like 500m. Nil wind and you might be lucky to reach 350m.
The number marked on the chart will probably be the max release height.
@Backpacker - thanks for the clarification!
You're welcome. And sorry about my last sentence. It might have come across a little more condescending than intended.
