In 1942 over 1900 sea mines were placed around New Caledonia to prevent Japanese invasion. Some were removed at the end of the war but many are still in place.
In 2009 Divers from the Australian, New Zealand, United States and French Navy took part in Exercise Lagoon Minex where we removed approximately 100 mines from the main shipping channel into Noumea Harbour.
The mines were inactive but still contained up to 80kg of explosive so care was to be taken. On finding a mine we would either attach explosives and blow it in place or lift and tow it to deep water and release it to fall to the bottom.