Editing Sailing (section)

===Apparent wind velocity===
The term "[[velocity]]" refers both to speed and direction. As applied to wind, ''apparent wind velocity'' ('''V<sub>A</sub>''') is the air velocity acting upon the leading edge of the most forward sail or as experienced by instrumentation or crew on a moving sailing craft. In nautical terminology, wind speeds are normally expressed in [[Knot (unit)|knots]] and wind angles in [[degree (angle)|degree]]s. All sailing craft reach a constant ''forward velocity'' ('''V<sub>B</sub>''') for a given ''true wind velocity'' ('''V<sub>T</sub>''') and ''point of sail''. The craft's point of sail affects its velocity for a given true wind velocity. Conventional sailing craft cannot derive power from the wind in a "no-go" zone that is approximately 40° to 50° away from the true wind, depending on the craft. Likewise, the directly downwind speed of all conventional sailing craft is limited to the true wind speed. As a sailboat sails further from the wind, the apparent wind becomes smaller and the lateral component becomes less; boat speed is highest on the beam reach. To act like an airfoil, the sail on a sailboat is sheeted further out as the course is further off the wind.<ref name=Jobson>{{cite book | last = Jobson | first = Gary | title = Championship Tactics: How Anyone Can Sail Faster, Smarter, and Win Races | publisher = St. Martin's Press | location = New York | year = 1990 | isbn = 978-0-312-04278-3 | pages = [https://archive.org/details/championshiptact00jobs/page/323 323] | url = https://archive.org/details/championshiptact00jobs/page/323 }}</ref> As an iceboat sails further from the wind, the apparent wind increases slightly and the boat speed is highest on the broad reach. In order to act like an airfoil, the sail on an iceboat is sheeted in for all three points of sail.<ref name = Kimball>
{{cite book
 | last = Kimball
 | first = John
 | title = Physics of Sailing
 | publisher = CRC Press
 | date = 2009
 | pages = 296
 | isbn = 978-1466502666 }}</ref>