Important: this is measured above or below the first beam. The one you measured the point distance from. Doesn't matter if your span is 18 and you measured the point at 17 instead of 1. Above or below the one you measured the point from.
This is equivalent to a hook height setting, but it sets a minimum depth for the bridle. Good for getting under things. The final depth will likely be a few feet lower than what you set.
