Minesweeping made significant advancements during World War II. Combatant nations quickly adapted ships to the task of minesweeping, including Australia's 35 civilian ships that became auxiliary minesweepers. Both Allied and Axis countries made heavy use of minesweepers throughout the war. Historian Gordon Williamson wrote that "Germany's minesweepers alone formed a massive proportion of its total strength, and are very much the unsung heroes of the Kriegsmarine." Naval mines remained a threat even after the war ended, and minesweeping crews were still active after VJ Day.