The Osean Coastal Defense Force (OCDF) is a branch of the Osean Defense Forces. The Osean Coastal Defense Force, as its name states, is in charge of defending the Osean coast from air, land, or sea attacks. 
The OCDF most notably operated a series of Surface-to-Air (SAM) batteries along the Osean Coast. These batteries damaged a SR-71 Blackbird spy plane that penetrated the Osean Air Defense Engagement Zone of Cape Landers on September 24, 2010. The Osean Air Defense Force's Wardog Squadron intercepted the plane & the reinforcements.
The Osean Coastal Defense Force is most likely the equivalent of the United States States Coast Guard.