Canalul Dunăre-Marea Neagră
Arrested again in January 1951, he was interned by administrative order at the Danube–Black Sea Canal, being released in March 1952. Kept under surveillance, he was re-arrested in November 1955 and sentenced by the Military Tribunal in Timișoara to 6 months imprisonment. Transferred from the Timișoara penitentiary to the Jilava Prison near Bucharest, he arrived at the Oradea penitentiary in December, and was detained there until April 1956. Boca was banned from monasticism and Church activities and was constantly under the surveillance and harassment of the Securitate.