2.1. Wind and leeway
We define the leeway (windage) of an object to be the
drift associated with the wind force on the overwater
structure of the object as measured relative to the 10 min
averaged wind measured at 10 m height (or reduced to
this height). This coincides with the meteorological
convention for measuring surface wind and is consistent
with earlier work in this field (Hodgins and Mak, 1995).
It is observed that an object moving under the influence
of the wind will diverge to some extent from the
downwind direction due to balance between the
hydrodynamic lift and drag of the subsurface area and
the aerodynamic lift and drag of the wind.