Marine current power the rotation of the earth. The sun acts as the primary driving force, causing winds and temperature differences. Because there are only small fluctuations in current speed and stream location with minimal changes in direction, ocean currents may be suitable locations for deploying energy extraction devices such as turbines. Other effects such as regional differences in temperature and salinity and the Coriolis effect due to the rotation of the earth are also major influences. The kinetic energy of marine currents can be converted in much the same way that a wind turbine extracts energy from the wind, using various types
Winds in the Age of Sail Winds in the Age of Sail The captain of a steam ship naturally chooses the shortest route to his destination. Since a sailing ship is usually pushed by winds and currents, its captain must find a route where the wind will probably blow in the right direction. Tacking, i.e. using contrary wind to pull (sic) the sails, was always possible but wasted time because of the zigzagging required, and this would significantly delay long voyages. The early European explorers were not only looking for new lands. They also had to discover the pattern of winds and currents that would carry