Original vintage 1960's Rolex advertisement for the Rolex Submariner dive watch - "If you were working here tomorrow, you'd wear a Rolex." 
 
Dimensions: Roughly 8 inches wide by 11 inches high.
 
"It takes a special kind of man to face the silent perils of the marine underworld.  And he needs a special kind of watch: a watch he's willing to stake his life on.  Nothing less than a Rolex would do for the support crew of Deepstar, and for the pilots who take this 2-man research submarine down to 4,000 feet."
 
Project Deepstar
Deepstar 4000 was a U.S. Navy/civilian deep-submergence vehicle designed by Jacques Cousteau and built by Westinghouse in 1965 and retired in 1972.  Deepstar 4000 was designed to take a crew of up to three to a depth of 4,000 feet (1,200 m), or over 665 fathoms (hence the name, Deepstar 4000).
 
Originally intended to have a 12,000 ft. depth rating, problems in manufacturing the hull resulted in a design change to materials that would allow only a 4,000 ft. rating.  Construction was completed in 1965, and testing began late that year.  A meticulous diving log was kept by pilot Ron Church, which starts with dive number 30, made December 1965.  In March 1966 a dive off San Diego, California reached 4,132 feet, likely its record depth.
 
During much of its operational life, Deepstar 4000 functioned under contract to the US Navy through the Navy Electronics Laboratory.  When submersible certification was introduced by the Navy, Deepstar was the first commercial unit to receive certification.
 
Some of the explorations of Deepstar 4000 were shown in the January 1971 edition of National Geographic – at the time of the NatGeo article, Deepstar 4000 had already completed more than 200 dives in the Atlantic, Pacific, and Caribbean. Even this large number of completed dives appears to be understated – in R. Frank Busby's book Manned Submersibles, it’s stated the Deepstar 4000 "conducted some 500 dives from June 1966 through June 1968."
 
The U.S. Naval Oceanographic Office used Deepstar 4000 for 13 dives during October and November 1967 to study marine geology, biology and the physical properties of the water column.  These dives were accomplished along the east coast of the United States and in the Caribbean, with great similarities in the bottom features at widely separated sites as well as dissimilarities in adjacent areas being the most noteworthy.
 
During this operation Deepstar 4000 was evaluated as a Deep Oceanographic Survey Vehicle (DOSV).  The lack of an all-weather capability and the rather limited payload hampered this study, but the overlapping fields of the viewports and the ability to operate in very close proximity to the bottom, regardless of terrain, were noted desirable features of the craft.
 
Accurate measurements of in-situ sound speed, temperature, salinity, and pressure have been achieved during numerous replicating dives aboard Deepstar 4000 to depths of 1,200 metres (3,900 ft).  Crewed deep submergence vehicles offer optimum methods for observing the actual ocean environment.
 
On one 1967 Deep Star 4000 dive south of San Diego, California, the crew, Dr. Eugene C. La Fond and pilot, narrowly escaped tragedy when the ascent system and its backup failed at 3,500 feet down.  The weights normally meant to detach to allow ascent would not release. To save the craft, hundreds of pounds of mercury ballast used for trim was hand pumped onto the ocean floor and the craft could rise.
 
The year previous, a crew member of the Deepstar 4000, Joe Thompson, claimed he had observed an unknown fish of extreme size while onboard the vessel.  According to his account, the giant fish was observed in 1966 by himself and briefly by one other crew member while off the coast of San Diego.  Thompson claimed to have observed the fish while placing equipment on the sea floor and glancing outside his window. H is description was that it was bigger than the submarine itself, with fish scales the size of coffee cups, and that its eyes were larger than dinner plates.  According to Thompson, it quickly swam away before any crew member could get photographic evidence of it. Following this account Thompson would continue to spread this story to others, such as cryptozoologist Gardner Soule.
 
And the Rolex Submariner?  Do we really need to discuss this legendary dive watch? 
 
Well, maybe we will for just a second - the Submariner is a line of sports watches designed for diving and manufactured by Rolex.  The first Submariner was introduced to the public in 1954 at the Basel Watch Fair, and was the first watch to be waterproof up to 100 metres (330 ft). 
 
The Rolex Submariner is considered "a classic among wristwatches," manufactured by one of the world's most widely recognized luxury brands.  Due to its immense popularity, there are numerous homage watches by well-established watchmakers, as well as illegal counterfeits. 
 
Today, the Submariner models are equipped with Rolex Calibres 3230 and 3235, respectively, and feature luminescent hour markers, a unidirectional rotatable bezel with Cerachrom ceramic insert, and a solid-link Oyster bracelet.  Also upgraded with time, since the mid-1950s?  Contemporary Submariner models underwater diving depth rating is 300 metres (1,000 ft).  Impressive, to say the very least.