12-metre class

The 12 Metre class is a rating class for racing sailboats that are designed to the International rule. It enables fair competition between boats that rate in the class whilst retaining the freedom to experiment with the details of their designs. The designation "12 Metre" does not refer to any single measurement on the boat, it is not their overall length for example, but to the sum of the components of the formula that governs design and construction. Typically 12 Metre class boats range from 65 to 75 feet (about 20 to 23 m) in length overall; they are most often sloop-rigged, with masts roughly 85 feet (26 m) tall.

The first 12 Metres were built in 1907. The 12 Metre class was used in the Olympic Games of 1908, 1912 and 1920 but few boats participated in these events. The 12 Metre class boats are best known as the boat design used in the America's Cup from 1958 to 1987.

Competitiveness between boats in the class is maintained by requiring the boats to be in compliance with the 12 Metre formula. Designers and builders are required to take into account such things as the sail area, the boat length at the waterline and the boat girth (the measurement around the boat from one sideboard, under the keel, and then over the top on the opposite side back to the original side). The measurements are then weighted in the formula. For example, the present formula takes the square root of the sail area rather than total area. The combination of weighted measurements must be less than or equal to 12 metres. Designers are free to change any of the component variables, as well as other details, such as the size of the rudder and keel, so long as the corresponding changes elsewhere produce an ultimate sum of 12 metres and the resulting boat is both seaworthy and safe. Though disparity between boats are minimized by the rule, enough variation exists so that races are as much about design and construction as they are about seamanship and tactics.

America's Cup

The America's Cup, affectionately known as the "Auld Mug", is a trophy awarded to the winner of the America's Cup match races between two sailing yachts. One yacht, known as the defender, represents the yacht club that currently holds the America's Cup and the second yacht, known as the challenger, represents the yacht club that is challenging for the cup. The timing of each match is determined by an agreement between the defender and the challenger. The America's Cup is the oldest international sporting trophy.

The trophy was originally awarded in 1851 by the Royal Yacht Squadron for a race around the Isle of Wight in England, which was won by the schooner America. The trophy was renamed the America's Cup after the yacht and was donated to the New York Yacht Club (NYYC) under the terms of the Deed of Gift, which made the cup available for perpetual international competition.

Any yacht club that meets the requirements specified in the Deed of Gift has the right to challenge the yacht club that holds the Cup. If the challenging club wins the match, it gains stewardship of the cup.

North America

North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It can also be considered a northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea.

North America covers an area of about 24,709,000 square kilometers (9,540,000 square miles), about 16.5% of the earth's land area and about 4.8% of its total surface. North America is the third largest continent by area, following Asia and Africa, and the fourth by population after Asia, Africa, and Europe.

In 2013, its population was estimated at nearly 565 million people in 23 independent states, or about 7.5% of the world's population, if nearby islands (most notably the Caribbean) are included.

North America was reached by its first human populations during the last glacial period, via crossing the Bering land bridge. The so-called Paleo-Indian period is taken to have lasted until about 10,000 years ago (the beginning of the Archaic or Meso-Indian period). The Classic stage spans roughly the 6th to 13th centuries. The Pre-Columbian era ended with the arrival of European settlers during the Age of Discovery and the Early Modern period. Present-day cultural and ethnic patterns reflect different kind of interactions between European colonists, indigenous peoples, African slaves and their descendants. European influences are strongest in the northern parts of the continent while indigenous and African influences are relatively stronger in the south. Because of the history of colonialism, most North Americans speak English, Spanish or French and societies and states commonly reflect Western traditions.