Hello Dave,

To illustrate the scale of the problem, the British laid over 185,000 mines for protective purposes in all theatres of war during World War II and over 76,000 mines in enemy waters. The Germans laid over 120,000 mines and 30,000 minesweeping obstructors in north-western Europe alone plus many more in the Mediterranean. As others have pointed out, it was impossible to keep track of them, especially moored mines that failed to separate from their sinkers or broke adrift and were moved by winds and currents.

That said, British minesweepers did keep a tally of the number of influence (magnetic and/or acoustic) ground mines they swept immediately after specific aerial minelays because they knew how many mines each type of aircraft carried in a 'stick'. They also had the reports of 'minewatchers' on clifftops to help them.

Best wishes,

Rob Hoole
[www.mcdoa.org.uk]