Between the 1970's and 80's Japan-made quartz watches literally vanquished European watchmakers by bringing revolutionary change in the watch industry. Back then it was nothing but a victory of innovation that a small button battery was all it takes to keep precise time for a year or two.

During this period many Japanese watch companies produced tens of thousands of different quartz watches because it was good ol' days when supply couldn't meet the fast expanding demand. Thanks to this favorable condition some of very experimental watches were also made available in the market, among which was Seiko's 'Field-master.'

As a vivid manifestation of the Japanese tendency for small-space compression during the 80's, this watch encased 2C21 quartz movement normally used for female watches. As a result, Field-master has a unique, almost toy-like atmosphere even though it is a full-fledged expedition watch by any standard. The watch is composed of two PVD-coated stainless steel cases hinged to each other. 

The watch part in the upper case is permanently fixed, but the lower case is designed for different tools exchangeable according to wearer's need or environment. Basic kit included compass, map meter (to measure actual distance on a scaled map) and digital alarm clock, but LCD alarm tool was only included in the package for Japanese domestic market and international version had only two optional tools.

Because of the small 28mm size case and equally tiny accessory window, customers thought this watch as a toy rather than a professional purpose watch, so it was almost being forgotten from the people's mind..

But there was an unexpected surge of demand for this intriguing watch in the late 80's, strangely enough, thanks to the Cold War on its peak. When Nicaragua turned against US after its communist revolution and turned into an increasing security threat, American administration decided to provide financial and logistical support for a pro-American insurgency group in Nicaraguan jungle known as 'Contras'.

As a way of operating one of those 'proxy wars' during Cold War era, US intelligence agency secretly supplied Contra guerrillas with tremendous amount of money and equipment, and along with them surplus stock of Seiko Field-master watches procured from Japan went into the hands of the Contras. Later, America's ugly face was exposed as CIA supported even Contra's drug trade, but this interesting historical background created among watch collectors a frenzy about its design and functionality, hence earning a nickname 'guerrilla watch.' Seiko Field-master is now one of the most wanted collectible time pieces, and  very rare to find in the market.