By Dave Moran
Images supplied by ENL, E Stevenson, D Moran, and M Fraser.
The trace line on the magnetometer’s screen disappeared off the bottom of the screen but the readout numbers kept dropping, -77 -73 -62 all the way to -4 then they started to climb, +13 +25 +35, the trace line reappeared and started to climb all the way up till it disappeared off the top of the screen. The numbers continued to climb, eventually reaching +138 before they started to descend. ‘Man this is it’ cried Ewan Stevenson.
‘Joe, keep her running on this course’ I yell to the skipper, ‘let’s see if the mag’s trace line returns to the baseline’. It did.
So ended days of anticipation and questions. Was the WASSP’s (Wide Angle Sonar Seafloor Profiler) target a wreck or just another reef poking its head above a desert of sand?
It was 11.30 am Monday 19 April 2010, some 92 years and 10 months since the 102 metre, SS Wimmera’s stern was ripped apart by two German mines and she succumbed to the rushing waters that devoured her soul and 26 other souls at 5.15 am on 26 June 1918 during World War 1.
All on board MV Acheron were elated that the search for the victim of the German Rader SMS Wolf had finally achieved its goal some 17 nautical miles (approx 30km) off New Zealand’s North Cape.
The Wolf’s escapades around New Zealand came to light after researcher Mike Fraser became aware of the Wolf’s activities while working for New Zealand MetService on Raoul Island in the Kermadecs Group. He learnt that the Wolf had sunk the SS Wairuna and the schooner Winslow off these islands and that there were two other Wolf victims striking mines off New Zealand’s coast: SS Port Kembla and SS Wimmera.
His research led him to the German Military Archives where he discovered that the captain of the Wolf, Karl Nerger, had written for wartime propaganda a book (1918) of his successful exploits over the 451 days he and his crew were at sea. Mike has republished this very entertaining book in English. He also uncovered the Wolf’s wartime log and marine charts showing the navigational marks (required by the 1907 Hague Convention) of the two mine fields laid in waters frequented by shipping departing or arriving from Australia – Farewell Spit and North Cape.
Mike successfully plotted the mine field off Farewell Spit and in February 2007 the SS Port Kembla’s bell was recovered by divers Pete Mesley and Simon Mitchell. (view April/ May 2007 Issue #99)
The success of this expedition encouraged Mike to further investigate the sinking of the Wimmera and its possible location. From the Court of Inquiry about the tragedy, Mike learnt the position that the second officer considered the Wimmera sunk. Laying this and the ship’s course, plus the mine fields coordinates, onto a modern day chart he was over the moon to see all three lines just about formed a perfect X, smack bang on the mine field line!
The hunt, was game on!
Mowing the lawn while wreck hunting is not your usual Saturday morning blast around the house to earn brownie points from the one that has to be obeyed! At sea it can last for days even months – thats a lot of brownie points!
To mow the lawn successfully you need a system that can deliver an image of every bump on the sea bed plus information such as: length, width, height off the sea bed, hardness and orientation to the compass etc.
…Read the full version in the June/July 2010 issue #118