Shallow Survey: Not the Lead Line Anymore

Advancements in shallow survey techniques will be the focus for over 200 international hydrographic and marine charting experts and other scientists when they gather in Wellington, New Zealand 20th to 24th February 2012 for the 6th International Shallow Survey Conference. Techniques to detect hazards to enable safe passage for shipping have been around for thousands of years. During Captain Cook's exploration voyages (1768-1779) a lead-line was used. Nowadays techniques vary from sensors to airborne Lidar. 

The lead line includes a lead weight attached to a knotted rope and dropped into the water. The weight had a piece of tallow attached to the bottom that would collect a small piece of the seabed, helping to measure water depth and identify hazards when New Zealand's coastlines and harbours were charted 240 years ago.  Captain Cook was undertaking what is now called a ‘shallow survey'.

 

Accurate shallow surveys of ports and harbours are necessary to mark unseen hazards that may pose a danger to shipping and other commercial enterprises, and are also key tools in managing the marine environment and also for recreation. With close to 99% of New Zealand's trade carried by ship, accurate shallow surveys of our ports and harbours play a critical role in the country's economy.

 

LINZ's national hydrographer Adam Greenland (image) says that all three hosting organisations: LINZ, GNS Science and NIWA, are proud to be hosting this event for the first time. The programme planned, along with the high calibre of speakers presenting papers, will make this a memorable event.

 

The conference centrepiece is the ‘common dataset' sessions held at 1-2.30pm on Tuesday, 21 February 2012. This is a comparative study of data collected in a shallow water test area between May 2010 and May 2011; for this conference that's Wellington Harbour right outside the Te Papa venue. Hydrographic equipment manufacturers collect data using their latest technology and make that data available to conference delegates. Analysis of the common dataset highlights the relative merits and effectiveness of the various shallow-water surveying techniques and products, and allows rigorous comparison.

 

To acknowledge the critical importance of shallow survey to the New Zealand economy and environment, NIWA's specialist shallow survey research vessel Ikatere will be alongside Te Papa for the duration of the conference. In addition, the Royal New Zealand Navy's hydrographic survey vessel HMNZS Resolution will be berthed at Queens Wharf from 17^th to 24^th February 2012.