Ranger 2 supporting deep-sea ROV operations from MBARI's R/V David Packard

The Monterey Bay Aquarium Research Institute (MBARI) completed the first ROV science dives from its new flagship, R/V David Packard in December 2025. This included navigating the remotely operated vehicle (ROV) Doc Ricketts through the coral gardens at Sur Ridge – a rocky seamount teeming with life off the coast of California – using Sonardyne underwater positioning technology. The expedition team successfully collected delicate deep-sea animals, showcasing the precision and reliability of integrated positioning systems in ocean research.

The challenge

MBARI’s ocean science depends on carefully observing, sampling, and revisiting specific deep-sea sites to understand change over time without disturbing fragile environments. This work requires scientists to know exactly where samples and observations are made.

Working far offshore and at depth, researchers must precisely track an ROV’s position relative to their vessel, the seafloor, and previous observations to interpret data and operate with confidence.

Ultra-Short BaseLine (USBL) positioning systems make this possible, using underwater acoustic ranging and telemetry to track, position, and control underwater assets.

Commissioned last year, MBARI’s 50 m (164 ft) long and 12.8 m (42 ft) wide R/V David Packard was designed to support this level of precision. Its USBL system provides the positioning that underpins safe vehicle operations, accurate sampling, and the ability to return to specific sites over time.

This capability is critical for operating ROVs such as MBARI’s 4,000-m-rated Doc Ricketts, as well as other instruments, platforms and vehicles researchers need to position on the seafloor.

Without a consistent positioning framework, long ROV dives, delicate biological sampling, and integrating data from multiple instruments would be far more difficult, reducing both cruise efficiency and long-term scientific value.

R/V David Packard recovers ROV Doc Ricketts after a deep-sea dive.

The Solution

Ranger 2 USBL was selected for R/V David Packard to support deep-sea science with a precise, repeatable and adaptable positioning across a wide range of missions.

As the vessel’s primary subsea positioning framework, it provides the ability to operate ROVs and other assets confidently at depth, supporting long-duration dives, delicate sampling and efficient use of limited vessel time.

Ranger 2 provides:

Precision at depth: Integration of Ranger 2 USBL with SPRINT INS already on the ROV Doc Ricketts enables stable, accurate ROV positioning down to 4,000 m (the ROV’s depth limit), supporting delicate biological sampling.
Advanced vehicle control: High-integrity navigation, supported by SPRINT INS, allows pilots to use auto hold and auto route functions during complex, close-proximity operations.
Operational flexibility: Supports simultaneous tracking and communication with up to 99 subsea assets at ranges up to 10,000 m.

MBARI’s skilled ROV pilots delicately collect corals and other deep-sea animals.

The Results

In December 2025, R/V David Packard conducted its first ROV science mission. It was a three-day collaborative expedition with MBARI’s education and conservation partner, the Monterey Bay Aquarium.

The primary goal was to explore a deep-sea coral garden at Sur Ridge, a rocky seamount off the coast of California, and collect animals—including comb jellies, balloon worms, and corals—now on exhibit in the Monterey Bay Aquarium’s ground-breaking Into the Deep / En lo Profundo exhibition.

Additionally, the expedition allowed MBARI’s marine operations team an opportunity to refine ROV operations, test manipulator arms and deploy a specialized “elevator” system for the safe transport of fragile animals to the surface.

Researchers explore the deep sea using ROV Doc Ricketts in the control room of MBARI's flagship research vessel David Packard.

During the Sur Ridge expedition, the integrated ROV and USBL positioning system performed as intended under demanding, real-world conditions during dives lasting up to 12 hours.

Following months of integration work, MBARI’s marine operations team successfully demonstrated stable, reliable positioning throughout long-duration scientific diving operations.

Accurate vehicle tracking and control enabled pilots to manoeuvre Doc Ricketts with the precision required to delicately collect fragile deep-sea corals and gelatinous animals using a navigation and positioning capability that enabled them to focus on discovery rather than system limitations.

“The Sur Ridge expedition marked a major milestone for MBARI, demonstrating our new flagship vessel’s ability to support extended ROV operations that are critical to our mission to advance marine science and engineering to understand our changing ocean,” said MBARI Director of Marine Operations Kaya Johnson.

R/V David Packard

R/V David Packard systems
Ranger 2 USBL System	The industry-standard USBL system used to track and communicate with up to 99 multiple scientific instruments and vehicles simultaneously at ranges up to 10,000 m.
HPT 7000 transceiver	Our deep-water transceiver integrated into the vessel to underpin its subsea positioning and communication capabilities.
Sonardyne Deployment machine	A specialized mechanism used to integrate and deploy the HPT 7000 transceiver through the vessel’s hull.

ROV Doc Ricketts systems
SPRINT INS	A subsea inertial navigation system that uses high-grade sensors and acoustic aiding to improve the accuracy, precision and integrity of vehicle positioning.

Sonardyne heritage with MBARI R/V vessels

Sonardyne’s relationship with MBARI spans more than 30 years, beginning in the early 1990s when MBARI became an early adopter of Sonardyne’s first USBL system on its inaugural research vessel, Point Lobos.

Since then, Sonardyne positioning and navigation technology has been progressively integrated across MBARI’s fleet and subsea platforms, supporting the institute’s evolving scientific goals.

Successive research vessels have carried this capability forward, from R/V Western Flyer—which transitioned from early USBL systems to the industry-standard Ranger 2—to MBARI’s new flagship, R/V David Packard.

At the vehicle level, MBARI’s ROVs Doc Ricketts and Ventana use Sonardyne SPRINT INS to enhance positioning accuracy at depth, while Doc Ricketts is also supported with a Lodestar AHRS and ROV Homer transducer.

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