sentences:  A submarine surfaced a few moments later, off, and fired a warning shell that passed overhead and landed in the water ahead of the ship.Krantz ordered the ship to full speed, hoping to outrun the attacker, and steered a zig-zag course.The sub fired a few more shells that missed, but then refined its targeting and barraged the "Puritan" with about 70 hits over the course of about 25 minutes.