With the Boxfish Remotely Operated Vehicle (ROV), port authorities can perform underwater inspections and video surveys regularly and efficiently without incurring prohibitive costs.

Ports of Auckland (POAL), New Zealand, was looking for an ROV to conduct a video survey to identify and map underwater ecosystems and habitats. The organization was awarded marine disposal consent to deposit dredge spoil at a site 27 nautical miles east of Cuvier Island, east of Auckland.

Approval was conditional on a prior seabed imaging survey of an area to the north to identify if rare or vulnerable ecosystems or species were present. The survey site was challenging, being a long way offshore and reaching depths of 710 meters.

The team looked at a few survey options, including a large work class ROV traditionally used in oil and gas operations. However, they were particularly impressed with the Boxfish ROV due to its compact size, easy-to-use technology, and crisp video and image capabilities. Additionally, the Boxfish ROV has a large capacity built-in battery and is depth rated to 1,000 meters, making the vehicle ideal for the POAL project.

Deep-Sea Observations

During the deployment with the Boxfish ROV, POAL surveyed 15 kilometers of transects between 490 and 710 meters. Due to the working depth, the ROV was parked in a weighted aluminum cage for the ascent and descent. The team validated that running transects up to three kilometers on a single battery charge was practical at this depth.

Once the system was positioned over the desired survey area, POAL released the ROV and reversed it out of the cage. The team then investigated seafloor features using the ROV's advanced image and video capabilities.

During deployment, it was important for the team to know where the surface vessel was in relation to the underwater ROV. Therefore, the vehicle ROV was equipped with a USBL (Ultra Short Baseline) Blueprint Subsea Seatrac system to provide subsea positioning information to the vessel's pilot.

A still from the Boxfish ROV video footage captured at 675 meters deep. (Image credit: Boxfish)

The USBL was invaluable during the mission, ensuring the team was positioned on the desired transect and recorded the precise vehicle location within the survey transect. By fitting beacons, rated to 1,000 meters deep, to the vehicle and cage, the team could track the position of the ROV underwater in real time.

Scientists monitored the ROV's high-resolution live video feed allowing them to make substrate and faunal observations in real time. Further analysis onshore included capturing and reviewing high-resolution 8MP images to confirm faunal identifications. Plus, more detailed studies of selected transects to determine the presence or absence of sensitive environments. The images from the survey were tagged with latitude, longitude, and depth using data from the USBL system.

The ROV's height above the seafloor was about one to two meters, and the vehicle angle was pitched downward at typically 30 degrees. The team also adjusted the pitch during the survey to suit the changing—sometimes unpredictable—water conditions.

"On the trip, the Boxfish team have been really practical and have been able to adapt to changes really easily," said Paul Kennedy, Environmental Consultant. "And so, we've managed to make a number of equipment changes on the spot, quickly, which has helped us get through things faster and keep on time."

Mission in Numbers

During the survey, 4K video was collected at the surface and recorded directly to a high-speed SSD device. The team logged the data regularly and recorded the following impressive results:

• A total of 15 dives were conducted
• Max depth reached was 710 meters
• 1,000 meters of tether deployed
• Up to 550 meters of horizontal separation—Boxfish ROV to boat
• 15 minutes for boat-to-seafloor deployment at 610 meters
• 75-minute deployment-to-recovery time per transect

After completing the survey, POAL scientists prepared a comprehensive environmental report identifying and quantifying all living species in the offshore site area. They were able to characterize the faunal communities along a series of transects 1, 3, 4, 5, and 20 kilometers from the disposal site boundary. The report concluded that there was no evidence of vulnerable marine ecosystems within the survey area.

"While we had an idea of what might lay beneath the surface, due to published data, the Boxfish was able to confirm the environment at 710 meters depth for us,” said Nigel Ironside, Senior Environmental Advisor at Ports of Auckland.

A World-Class ROV

The industry-leading observation class Boxfish ROV is a unique solution for underwater inspection and video surveys. The vehicle is portable, lightweight (24 kg), and can be lifted and deployed by a crew of two. At the same time, it is capable of operation and precise positioning in heavy currents thanks to a patented active stabilization system.

The ROV delivers 4K live video from depths of up to 1,000 meters and can be integrated with a range of accessories due to its flexible, modular design. Optional ROV add-ons include a USBL (Ultra Short Baseline) positioning system, multibeam imaging sonar, and a DVL (Doppler Velocity Log) to enhance vehicle navigation, control, and tracking.

The Boxfish ROV has an eight 3D-vectored thruster layout that offers the unique capability of true six degrees of freedom of movement, meaning the vehicle can travel and orient itself in any direction. The automatic stabilization system makes piloting the ROV extremely easy and intuitive and delivers super smooth and clear sensor data and imagery.

Innovative Research

Boxfish Research designs and manufactures industry-leading, actively stabilized, ultra-high-definition remotely operated and autonomous capable vehicles for submerged asset inspection, marine science, expedition superyachts, offshore energy, aquaculture, biosecurity, search and rescue, and cinematography. Boxfish Research incorporates innovative technology with ease of use and advanced sensing to expand the possibilities for humans to understand, experience, and work within the underwater world.

Learn more about this Boxfish ROV case study: https://www.boxfish.nz/case_study/deepsea-deployment/

This feature appeared in Environment, Coastal & Offshore (ECO) Magazine's 2023 Spring edition Sustainable Ocean Exploration, to read more access the magazine here.