The Rolex Yachtmaster II is a very peculiar watch in that it's just so spectacularly different to every other watch in the 'Oyster Perpetual' family that Rolex makes! It's like some rebellious sea-faring child of the Titan 44mm Deepsea  and the more sophisticated 40mm Yacht-Master.
Throughout wristwatch history Rolex have forever been at the forefront of innovation. They are known as the first major manufacturer of a completely water-resistant divers watch thanks to a series of landmark publicity stunts to promote their brand. They put another mark into the history books with the Datejust that automatically adjusted the date by itself - an unheard of accomplishment at the time. And they are also attributed with the first watch to show two-time zones with the GMT master.