NIWA use Tritech Towfish Sonar to Survey Cruise Liner Wreck
The wreck of the Lermantov Russian luxury cruise liner lies off the coast of the north tip of New Zealand's South Island and is one of the largest and most accessible recreational diving wrecks today.
The Lermantov had embarked from Sydney on "a two week cruise of a lifetime" in 1986 and was in New Zealand waters when disaster struck. The hull of the liner was torn open on the rocky reef of the Marlborough Sound and, unable to beach her due to engine failure, the Russian Captain watched his ship sink at Port Gore, 35 miles from Picton. Of the 743 passengers and crew on board, one young engineer lost his life.
Ken Grange of internationally respected research organisation NIWA (National Institute of Water and Atmospheric Research), New Zealand, is familiar with the unfortunate story of the Lermantov. During a recent project studying nearshore marine habitats he decided to take the opportunity to tow the Tritech SeaKing Towfish down the side of the wreck.
"The operating conditions were good and the Towfish sidescan was dragged behind a small launch at 2 knots with a swath of 50m either side. The sidescan log file was interfaced with a hand-help Garmin GPS, with both the skim box and GPS plugged into a laptop running SeaNet Pro. The resultant V4log file was converted to xtf using Dumplog Pro and the xtf file was post-processed using Triton ISIS software. The final output was a geo-referenced tif file using the vessel speed, Towfish layback, and GPS." Ken Grange, NIWA
Tritech's SeaKing Towfish is an extremely compact high definition sidescan sonar system designed for a wide range of seabed survey and inspection duties. The future direction of this product is very positive especially as Tritech intends to introduce DST (Digital Sonar Technology) to the acoustic engine of the SeaKing Towfish. DST will provide, amongst other things, greatly improved range resolution.
Tritech International would like to thank Ken Grange and NIWA for providing the image and log data for this article.
Learn more about Digital Sonar Technology and the Tritech Seaking Towfish Sonar
For more information about the Lermantov go to www.nzmaritime.co.nz/lermontov.htm
