22.09.15 Subsea Treasure Hunting

In 1860, a daring rescue saved all 592 passengers and the crew of the SS Connaught before it sank with its cargo of gold coins. One hundred and fifty five years later, Seatronics' Predator remotely operated vehicle (ROV) negotiated strong bottom currents and hazardous fishing debris to play a pivotal role in verifying the ill-fated, treasure-laden liner’s resting place. It delivered considerable value for Endurance Exploration Group Inc. by performing beyond the expectations for the inspection-class ROV.

Endurance Exploration Group aims to create shareholder value by recovering valuable merchant cargoes. The search for the SS Connaught was the company’s first offshore operation after five years of desk-based research and its first opportunity to show a return on investment. With “pay day” some way off, controlling project costs was high on its agenda.

Flood, Fire and Fruit

The 380-ft SS Connaught was one of the largest and most-luxurious oceangoing mid-nineteenth-century liners. Disaster struck on 25 September 1860 when the ship sprang a leak in a sudden storm while sailing from St John’s, Canada, to Boston, USA. The leak was brought under control, but a fire forced the people onto the top deck. When the lifeboats smashed on being lowered into the sea, there seemed little hope for the passengers and crew.

Fortunately, a small fruit transport ship steamed to the rescue. An escape line was secured between the vessels and, following tradition, the captain left last. Everyone squeezed onto the merchant vessel, which took them to Boston’s India Warf, but more than 4500 kg of gold coins went down with the liner: money thought to have been for visiting British royalty.

The loss of the SS Connaught on only her second voyage was a disaster, but the courageous rescue, without a fatality, was a triumph of courage and seamanship.

Predator: Punching Above It's Weight

The SS Connaught lies in 200 m of water in an area of strong, difficult-to-measure bottom currents and has collected a tangle of fishing debris over the last century and a half. The Seatronics Predator inspection-class ROV, supplied by Great Eastern Group, was selected as a cost-effective option for verifying the wreck as the SS Connaught.

“Given the conditions, a mid-class ROV would normally be required for such a seabed inspection, but that would have escalated costs dramatically,” explains Euan Mackay, vice president, sales, Seatronics Inc. “The client would have required a much larger support vessel and team and ancillaries if a mid- or work-class vehicle had been used. The Predator ROV did a difficult job reliably and cost-effectively, considering the conditions. It proved its worth.” Bruce Morris, director of engineering and operations, Great Eastern Group, coordinated the verification project. He says, “Because it is small and light, two people can launch the vehicle. It is easier with a crane, but, in this case, we simply slid the vehicle off a ramp that was previously fabricated for the stern of the vessel.

“The Predator vehicle was easily held on station in the 2.5–3-kn. bottom currents with the powerful thrusters at 80% gain, which illustrates the current strength. Its exceptional thruster control and power output gave the vehicle a high degree of manoeuvrability in these challenging conditions. We got great feedback from the operators, who likened ‘flying’ the vehicle to playing a simple video game. At low speeds, it can be carefully nudged forward for great close-up images.”

Mackay adds, “And that was a fly-alone Predator. Customers can also use the Predator ROV with station-keeping software from our partner SeeByte Ltd that automatically holds the ROV at the correct depth and attitude and enables it to fly on predetermined courses. Other ROV manufacturers are working on similar systems, but we have the lead and believe we have the best solution in SeeByte software, which is calibrated to the Predator vehicle for exceptional stability.”

Another advantage of the Predator system is its flexibility. Morris says, “On-the-job modifications are common. When we get to a site, suddenly there is a requirement that no one anticipated, so you need to be able to recover the vehicle to the deck and customise it. Predator gives you that freedom. You can make simple modifications that can accommodate various bolt-on tools and sensors.”

The ROV’s first work was for the offshore wind industry and it is now used in many diverse applications, including in the oil and gas, and naval sectors. Law enforcement agencies also use it for search-and-rescue operations, and crime-scene investigations – work that otherwise places divers at risk.

Morris continues: “The Predator ROV has a network control system that uses comprehensive diagnostics to assure continuous operation in challenging conditions. High-capability diagnostic electronics more typical of work-class ROVs monitor all the vehicle’s functions and identify fault sectors without loss of ROV control. Reliability is important, but so is the ability to perform on-deck maintenance. If your ROV suffers a catastrophic failure early in a job, it can be a financial disaster: a wasted trip.

“The Predator system comes with a comprehensive spares kit and is built from plug-and-play components. The SS Connaught project is a great example. The impellors sucked fishing lines in three times, but each time the Predator ROV freed itself thanks to the design and power of its thrusters. As a precaution, the damaged thrusters were switched out in a simple five-minute job. Less powerful ROVs might have been irrecoverable or lost, with huge financial implications for the project,” he concludes.


In 2013, Endurance Exploration Group performed a 1800 km2 side scan sonar search of the area where the SS Connaught was thought to have gone down. A year later, it teamed up with Eclipse Group Inc. to investigate an encouraging signal 160 km off the north east US coast. Eclipse provides subsea technical solutions, which, in this case, included deploying a Seatronics Predator ROV to verify the wreck. Between them, Seatronics and Great Eastern Group provide global support.

The Predator ROV clearly identified the SS Connaught s iron hull and paddle wheels, and artefacts within the debris field, including 150-year old whisky bottles. Initially, it surveyed the wreck in the zero-visibility conditions using sonar before switching on its cameras and lights.

Recovering the cargo

Endurance Exploration Group is now seeking the legal right to salvage the cargo robotically before the wreck suffers further trawler damage. If this is granted, the company plans to return to the site in spring or summer 2015 to begin a systematic and well documented recovery of the cargo and artefacts.

In addition to recovering the valuable cargo, Endurance Exploration Group plans to make a television documentary to tell the remarkable story of the SS Connaught and the courageous rescue of all its passengers and crew. No doubt, Seatronics’ Predator will have a starring role.

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