Underwater ocean gliders can be a window into the unknown – providing insight into the behavior of marine life, tracking storms, or collecting subsurface information that is vital to naval operations. They can offer unparalleled access to ocean measurements on large scales.

Our client, Hefring Engineering, is re-imagining this essential tool for ocean observation and research with their new product, Oceanscout.

“For a long time ocean gliders have been very expensive, cumbersome and complex, while relying on technologies that have been around since the 1970s,” explains Micheil Boesel, Engineering Manager at Hefring Engineering. “Our founders knew there was a market need for an autonomous vehicle that could significantly expand the use of ocean gliders and do so at a more affordable cost. That’s where it all started.”

Hefring Engineering started work on their mission in late 2019. At first, they worked out of a small office space in Boston before expanding their team and moving up the coast to Gloucester, Massachusetts, in May 2021.

“The starting point was to understand our key markets and what they needed. There are a range of applications for an ocean glider but the overall cost of ownership was consistently the biggest obstacle to people using them. Making it more affordable was our first goal and thanks to the work of our team we anticipate being able to get gliders down to a fifth of their usual cost.”

“But that’s not all. We wanted to make the base model adaptable so it could best suit the user,” adds Mr. Boesel. “There is so much in the ocean to measure and being able to characterize large domains with an easily scalable platform is the way to go. We’ve managed to do that. We carefully select the most appropriate sensors for each use case and ensure they work in concert with the vehicle electronics. If you can drop one in the water, you can view data in no time!”

A new standard

It’s this scalability that makes Oceanscout so appealing to different sectors.

One of the exciting applications for Oceanscout is in observing mammals and sealife in a non-invasive way. The first mission-specific model of the Oceanscout has been developed specifically for passive acoustic monitoring. This means that the glider is provided with a high-quality hydrophone, electronics to amplify, digitize and record the sound, and a mid-range CTD (conductivity, temperature, pressure (depth) sensor.

Dolphins, for example, communicate via ultrasonic clicks and whistles and the Oceanscout will allow researchers to listen in to a pod and better understand their movements. The Atlantic white-sided dolphin, for example, is native to the Atlantic waters near Hefring’s headquarters and considered to be under threat by anthropogenic noise and pollution – research into their behavior could well be a beneficiary of the new glider.

A CT sensor is also standard on all Oceanscout models – and is particularly useful for improving the accuracy of storm models. It is used to collect sound speed profiles, assimilation data, and CTD transects. Better storm models can prove advantageous for developing more accurate early warning systems and understanding the impact of a changing climate.

Whatever the glider is used to measure, the information can be sent in real time by satellite or other means to provide immediate insight to decision makers.

Oceanscout’s tail holds its communications modules. It extends its Iridium antenna above the surface and allows for other communication options, such as radio, if required. Integrated GPS and beacon allow easy location of the glider for retrieval.

“That seamless relay of data, and how it is delivered to the end user, was another key part of our development process,” says Mr. Boesel. “Our software developers have created a slick web interface to help users navigate this information in real-time. And what’s more, piloting the glider is made easier too – you can set waypoints for Oceanscout to follow without need for expertise.”

Powering greater missions

The glider’s range varies by mission (depending on the regularity of data being collected, for example) but it can travel up to 1,000km at a time.

Having such a large range and being propelled by three motors, though, requires a significant and reliable power source.

“We explored a few options for power in the early stages of development,” says Mr. Boesel. “My first thought was to explore alkalines but we figured out pretty soon that they weren’t going to work. The peak power of those three motors is pretty high so we moved our attention to lithium cells and the different chemistries, before settling on lithium manganese dioxide for the strong energy density and additional safety factors.”

“When we started to ask people about these batteries, wanting a supplier with an excellent track record, people just said ‘Saft’. They were very well respected in the field. That journey has been everything we hoped, flawless in fact. The datasheets line up with the performance we’ve seen and it’s perfect for Oceanscout. We have seven packs of twelve cells in the glider and a nominal voltage of 36V - with that comes a need for reliability in each and every cell and there’s no margin for error.”

The standard 1.8KWh lithium battery pack uses 84 LM26500 Saft batteries and will power Oceanscout missions for over two months (depending on configuration). These packs can be quickly and easily replaced and offer strong value for money – reducing the total cost of ownership and operation for the glider user.

Launching in late 2023, the Oceanscout will make subsurface ocean measurements available to more. With the health of sealife a growing concern, and the ever-present need to learn more about our oceans, the new glider could not have come at a better time.