sentences:  At night, she functioned as a guard and escort vessel; then, as sunrise came, she began daily exploratory sweeps, searching for moored, magnetic, and sonic mines in the harbor and its approaches.At times, severe weather or low visibility forced "Trident" to secure from sweep operations; and, in foggy weather, she helped to regulate harbor traffic.Continuing instruction, drills, and periods of repair broke the minesweeper's routine.