Our core business involves hydrographic survey services, however our skills extend beyond waterborne activities to include surveying services in the wider coastal and in-shore environment. We employ experienced land surveyors to assist in projects where land and sea activities overlap to provide a complete solution. We have become adept at achieving the fine balance between good quality data coverage at a reasonable cost. DML engages marine scientists specialising in biological and environmental monitoring and Resource Consents for specialist projects. We have built long term alliances with specialist diving teams and the University of Waikato, Coastal Marine Group.


survey platforms


We specialise in providing:

  • Multibeam & singlebeam hydrographic surveys to IHO standards
  • 3D Imaging both above & below the water using a combination of laserscanning above the water and multibeam sonar below the water
  • Port and harbour development surveys
  • Sidescan sonar surveys for seabed inspection
  • Dredging pre, progress & post construction surveys used to calculate volumes for cost estimates and record actual dredge volumes for payments
  • Seabed classification & target detection
  • Lakes, rivers, reservoirs, dams and forebay surveys
  • Sub-merged infrastructure inspections including bridges, wharves and dams.
  • Aquaculture marine farm positioning & support
  • Shipping & salvage support
  • Environmental surveying for erosion monitoring & consents
  • Magnetometer surveys - detection of ferrous objects
  • Measurement of tides and currents
  • Sediment sampling
Survey platforms are carefully selected to suit the particular requirements of each project. We operate our own fleet of in-shore survey boats for harbour and coastal projects, ranging in size from 3-9m. These vessels are operated under the MNZ Maritime Operator Safety System (MOSS). Jet skis, kayaks and dinghys can be fitted with portable equipment for intricate jobs and we will also use remotely controlled platforms for difficult to access sites. Medium and large sized vessels are leased for larger off-shore surveys.

To achieve accurate and efficient results, DML uses state-of-the art survey equipment including;

  • High-accuracy GPS positioning systems (RTK, DGPS, WADGNSS)
  • Inertial motion sensors to remove vessel heave/motion
  • Digital singlebeam and multibeam echo sounders
  • Side scan sonar systems
  • Towed proton magnetometer
  • Portable environmental sensors and tide gauges
  • Static (land) and mobile (vessel/vehicle) laser scanning technology.
  • Airborne Drone for digital photography & reconnaissance

Data is collected using software capable of producing stand-alone sounding plans,
3D fly throughs and digital data in a variety of formats for integration with other digital and GIS systems.

Point cloud data gathered from Hydrographic & Topographic surveys can be used to produce 2D & 3D images from our modelling software.