Apparent wind that measures wind speed in knots and wind direction in degrees relative to the heading of the boat. Modern instrumentation can calculate the true wind velocity when the apparent wind and boat speed and direction are input. In sailboat racing, and especially in speed sailing, apparent wind is a vital factor, when determining the points of sail a sailboat can effectively travel in. A vessel traveling at increasing speed relative to the "prevailing wind" will encounter the wind driving the sail at a decreasing angle and increasing velocity. Eventually, the increased drag and diminished degree of efficiency of a sail
War Wind have to be promoted at a specific facility. Additionally, units could be individually upgraded in a variety of areas such as speed, strength, resilience, stealth, and vision. The purpose for these micro upgrades was to encourage more strategic and smaller conflicts instead making players simply building up units and "steam rolling" the opposition. Another unique aspect of war wind was stealth, there are four levels of stealth in the game. Stealth is always broken, regardless of level, when a unit attacks or is attacked. It will not be restored unless the unit remains out of combat for a period of