A suspected World War Two sea mine spotted by a jet-skier at
the entrance to Lyttelton Harbour has not been found after a
The jet-skier claims to have seen the semi-submerged
explosive floating near Port Levy, Banks Peninsula, last
week. He phoned police on December 31 who took the sighting
The local Coastguard, along with a New Zealand Defence Force
(NZDF) bomb disposal team, launched a wide-scale area search
the following day.
Inspector Derek Erasmus said the jet-skier described the
object as being the size of a wrecking ball, and thought it
may have been a mine.
"Coastguard and NZDF spent up to three hours on the water in
the area that afternoon, in similar conditions to when the
item was originally sighted, and taking drift modelling into
account. Nothing was located," Mr Erasmus said.
During the Second World War, there were fears that either
Hitler's Germany or the rampant Imperial Japanese Army would
invade New Zealand.
Enemy submarines were allegedly seen cruising up Lyttelton
Harbour in the early days of war.
Fort Jervois on the harbour's island of Ripapa was garrisoned
and the Godley Head battery was set up to counter enemy
vessels attempting to bombard the coast.
But ten 1000kg mines were successfully laid undetected by the
enemy German minelayer Adjutant in June 1941.
They were not moored but lay on the seabed and were designed
to detonate by the acoustic or magnetic activity of ships
Adjutant's minelaying was not successful. Thousands of ships
safely passed over the mines during the war - none were sunk
- and it wasn't until Germany surrendered in 1945 that the
existence of the minefields became known.
The navy believes that over the years the mines sank deep
into the seabed.
In 2010, navy dive ship HMNZS Manawanui searched the
sea-floor of the harbour entrance after port authorities
revealed plans to dredge a deeper channel. The search for the
mines came up empty-handed.
A spokesman for Coastguard Canterbury today, however, doubted
that the object allegedly seen by the jet-skier was a WWII
"If it was a mine, it could have come from anywhere. It could
have come all the way from Germany ... we're talking a long
time ago," said the duty officer who was involved in the
"Whatever they saw was covered in a lot of marine growth. But
who would know what it was.
"They (the jet-skier) suspected it was, the police took it
seriously, we had a pretty comprehensive search but couldn't
find anything resembling it remotely, so that's it."
The local Coastguard has not previously come across any mines
in the harbour.
Police have now contacted Maritime NZ and the incident has
been noted as a possible mine sighting.
"It is not possible to confirm what the item may have been,"
Mr Erasmus said.
- Kurt Bayer