Corsair. Oregon Files #6, Paperback/Jack B. Du Brul

Off the coast of Somalia a battered, old freighter is boarded by pirates whose sights are set on a hefty ransom. But these pirates have made a mistake. For this rusting freighter is none other than Juan Cabrillo's secretive, state-of-the-art fighting ship Oregon. And Cabrillo is about to turn the tables on a deadly Somali pirate captain.