sentences:  At 0718, as the two ships approached the waters most apt to be mined, every precaution was taken to minimize damage and casualties, should the ships strike a mine.The American sailors maintained a state of readiness to repel possible attack, as "Thomas J. Gary", with her sister ship 500 yards astern, threaded her way at nine knots through the unknown and dangerous waters.Four Combat Air Patrol planes provided cover, and two anti-mine sweep planes from the carriers relayed word of the sightings of possible mines as the destroyer escorts picked their way through the hazardous approaches to Kiirun, making frequent changes of course to avoid sonar contacts which exhibited a suspicious similarity to those made by mines.