Bruce Partridge never set out to dominate the technical computing market or create a recreational dive computer when he decided to build a computer that manages a rebreather’s oxygen delivery system. Having recently sold his company that designed computer systems for law firms and “retired” in 1996, the 41-year-old Canadian entrepreneur was happy teaching sailing and pursuing his newfound interest in tec and rebreather diving.

But after he spent some years living as a “gentleman diver,” his working fiancée, Lynn Stark, a fellow tec diver he had met on a dive boat, insisted it was time he got a job. Bruce decided he should make something—ideally, something involving diving.

In the early 2000s, tec diving was still relatively new and there were only a few computers on the market capable of handling mixed-gas diving—most tec divers still used tables, and tec rebreathers were still in their infancy. “I remember sitting in Grand Cayman for more than a half hour trying to set up this small wrist-mounted computer with conservatism and the right gas for a dive,” Partridge says. “I couldn’t believe how difficult and unintuitive the user interface was. So, I started looking at some of the other products on the market and realized that this was a common thread.”

In 2004, the year after they married, the Partridges released their GF Controller (the GF stands for gradient factors), which attached to a rebreather via a cable. They also incorporated their new company, Shearwater Research, in Vancouver, Canada, which they named after a predatory diving seabird, a naming convention they would repeat with future product offerings. They moved production into their spare bedroom, where it would remain for the next few years, and went to work.

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Building a Stand-Alone Tec Computer

After the release of the GF Controller, users requested that the Partridges build a stand-alone dive computer, capable of handling trimix (an oxygen, helium and nitrogen gas mix). The result, the GF, convinced the Partridges to continue their focus on tec dive computers. Beginning with the release of the monochrome Pursuit in 2006, the Partridges and their growing team delivered a series of increasingly capable dive computers every two to three years based on their design philosophy: powerful, simple and reliable. Each subsequent model became known for Shearwater’s intuitive user interface and improvements in terms of reduced size and weight, lower power consumption, and brighter, clearer displays.

As a result of their early successes, the Partridges were confronted with the reality of building technical diving gear—along with the inherent safety risk taken on by tec divers in the field. With this in mind, the Partridges brought in a team of world-class engineering talent to review and validate every piece of Shearwater hardware and line of code with its development team. They adapted a robust real-time serial electronics network used in military vehicles, called CAN bus, for use in rebreathers and dubbed it DiveCAN. As a result, in 2013, Shearwater received an International Safety Society Award for scientific achievement.

Having pioneered the use of adjustable gradient factors in dive computers, Shearwater’s engineering team continued to expand its computers’ capabilities, incorporating a series of tools that enabled tec divers to plan or modify their dive on the fly and provide them with real-time information underwater. The manufacturer was even also able to convince tec divers to use its wireless air-integration Perdix AI computer (2016) at a time when many techies were still suspicious of dive computers!

From Tec to Rec

In 2018, Bruce stepped down as CEO, tasking Jim Hartt to run the company. At that juncture, it seemed obvious that the company should consider creating a computer for the recreational market.

Shearwater clearly had the technology to address recreational divers’ needs; the challenge was cost. “We didn’t really look at chip or display costs when we were building tec products. But once you get into the recreational market, you have to be a little more cost-conscious to stay competitive,” Partridge says. In 2020, Shearwater launched its “brick style” Peregrine computer for recreational divers, priced in the $500 to $600 range. A few years later, the computer evolved further with the introduction of the Tern and Tern TX (“TX” for transmitter) watch-style computers for recreational divers. The company also moved to a new 35,000-square-foot facility in Richmond, British Columbia.

In 2021, the Partridges sold Shearwater but retained a minority ownership and a seat on the board. Two years later, Shearwater recruited waterman Jason Leggatt to take over as CEO. Under its new leadership, Shearwater continued to expand its offerings to recreational divers, launching the Tern and Tern TX watch-style computers in 2023. “We’re not inclined to always be the first mover with innovations,” Leggatt explains. “Rather, we have an intense focus to build things better, and if we can, build it simpler. That’s what ‘powerful’ and ‘simple’ in our slogan really means.”

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Last year, Shearwater began a strategic R & D partnership with innovative startup Avelo, which had developed a tank-based hydraulic system that enables divers to maintain neutral buoyancy without the use of a wing or drysuit by adding water to or removing water from the Hydrotank. This causes the tank pressure to change in ways a standard computer mode cannot manage. Shearwater’s “Avelo Mode” properly calculates actual gas consumption, buoyancy and real-time performance metrics when using a transmitter. Shearwater has since announced it would also manufacture an integrated Jetpack, which mates with Avelo’s Hydrotank to pull it all together.

“Most tec divers will acknowledge that their journey, their passion for diving, began with that first try-dive or open water class,” Leggatt says. “And if Shearwater is going to be the brand that they’re going to trust at the later stages of that journey, why wouldn’t we want to participate in introducing them to that journey from the beginning?”

What began with tec has clearly now expanded to support divers on their journey from their first dive to as deep, and far, as their training, knowledge, equipment and imagination will take them.