Port & Dredging Support

Port and dredging support surveys are an essential tool for the safety of shipping, port asset management, tidal modelling, water/sediment quality and resource consents. The surveys may consist of Single Beam Echo Sounder (SBES) surveys, Multibeam Echo Sounder Surveys (MBES), sediment sampling, tide gauge monitoring and analysis, ADCP surveys for current monitoring, pre and post dredging surveys, dredge monitoring surveys, dredge volume calculations and Mobile Laser Scanning (MLS) of wharves and port structures. The vessels used range in size from jetski's to purpose built survey vessels 5-7m in length fitted with state of the art positioning, motion sensors and portable survey computers.

Tauranga Harbour - Case Study

Client: Port of Tauranga I Duration: Ongoing


Port of Tauranga is New Zealand's busiest port and largest port by volume situated in the Bay of Plenty, on the east coast of the North Island of New Zealand's. It is a leading import/export destination currently investing in berth and infrastructure expansion projects including capital dredging works, which will attract larger vessels and increase container volumes.

Port of Tauranga operations extend beyond Tauranga to Metroport in Auckland, an alliance with North Port Corporation at Marsden Point, Metroport in Rolleston Christchurch and a 50% shareholding in Primeport Timaru.


The Tauranga Harbour is an extremely dynamic environment with harbour depths subject to frequent change. Located in the Western Bay of Plenty, the harbour is predominately shallow with strong tidal flows. Seaward of the 'mouth' of the harbour entrance, the region is often affected by large seas and swell at certain times of the year.

The Port of Tauranga undertakes regular maintenance dredging to ensure safe navigation and required Under Keel Clearance. DML undertakes pre and post dredge surveys on behalf of POTL to derive accurate baseline datasets. The data quality and level of coverage enables the accurate calculation of volumes which provides confidence to the Port Operations team in terms of assessing UKC. Other benefits include the on-going detection of targets/objects on the sea floor.

Given the busy and dynamic nature of a port environment, DML is on hand to provide other hydrographic support and advice including wider joint venture harbour surveys for research, recreational and local government use, updating of notices to mariners, assistance in emergency response situations and the management of a variety of stakeholder relationships.

DML has been providing contract hydrographic survey support and services since 2005. The contract services are supervised by senior IHO Cat A Surveyor/s. DML has established a long term relationship with POTL built on trust and exceptional customer service.


DML must work within tight tidal constraints and around shipping movements associated with a busy port, however given that DML's head office is located in Tauranga, the company is able to rapidly respond to as required to port needs.


DML guides and implements POTL's annual survey plan using a combination of Port assets supported as required by DML vessels and software. The Port also has a commitment to supporting the marine students from the University of Waikato which is often facilitated with the assistance of DML.


Discovery Marine Ltd
42B Tawa Street
Mount Maunganui 3116

Postal Address:
PO Box 4048
Mount MaunganuiĀ 
Bay of Plenty 3149
New Zealand

Tel: 0800 365 787 or


Discovery Marine Ltd
Unit 1, 15 Ashfield Street

Tel: 0800 365 787 or


Discovery Marine Australia Ltd (DMAL)

For all enquiries, please call the freephone number below:

Tel: 1800-625-317