Marine One is the call sign for any Helicopter that carries the President of the United States.

Some Marine One Trivia:

• Presidential helicopter transport is always handled by the special Marine squadron called HMX-1. There are over 700 Marines in the squadron.
• There are over 20 different aircraft in the current fleet, and there are several different models. The largest can transport 15 people. All of the helicopters are set to be replaced in the next few years.
• Any time Marine One flies, it is accompanied by 2 – 5 decoy helicopters. The choppers fly in a “shell game” pattern to throw off would-be attackers.
• Whenever the President travels in Air Force One, a detachment of helicopters flies with him, regardless of whether helicopter travel is planned or not.
• Wherever Marine One lands there is a ceremonial Marine Guard waiting to greet him. One time Bill Clinton requested an impromptu landing in the Grand Canyon and was surprised to see a Marine waiting to greet him.
• When the helicopter lands on the South Lawn at the White House, there are 3 precisely positioned discs, each 6 feet in diameter, that the pilot must land the wheels on. This ensures that the helicopter is in the correct position. The discs also help distribute the weight of the helicopter, so that it doesn’t make holes in the lawn.

Bonus Trivia: The United States is the only country that provides its chief executive with his own transportation anywhere in the world.

Source: National Geographic Channel