Ted Eldred: The Forgotten Father of the Modern Scuba Regulator
Buddha Weber Nov 07, 2026
When most divers hear the name Aqua-Lung, they immediately think of Jacques Cousteau.
And for good reason.
In 1943, Cousteau and French engineer Émile Gagnan developed the Aqua-Lung, a revolutionary demand-regulated system that allowed divers to breathe compressed air underwater without being connected to the surface. It changed diving forever.
But there is another name that every diver should know.
Ted Eldred.
An Australian engineer and passionate diver, Eldred saw the limitations of the original twin-hose Aqua-Lung and set out to build something better.
At the time, the Aqua-Lung was protected by patents, and the regulator's design used two large breathing hoses. One delivered air to the diver while the other carried exhaled air back to the regulator behind the diver's head.
Eldred took a completely different approach.
Instead of putting the demand valve behind the diver's head, he developed a system that brought intermediate-pressure air from the first stage through a single low-pressure hose directly to a second-stage demand valve at the diver's mouth. Exhaled air was then released through the second stage.
It was smaller, simpler, and much closer to the configuration divers recognize today.
Eldred called his invention the Porpoise.
By 1952, he was commercially producing his single-hose scuba system in Australia. The Royal Australian Navy eventually adopted the Porpoise Universal, making it the first navy to be equipped with a single-hose scuba system.
And here's where the story gets interesting.
Eldred's design was developed in part to avoid the patents surrounding the Cousteau-Gagnan Aqua-Lung. His company was small, however, and he never patented his own regulator design, reportedly because the cost was beyond what his business could afford.
The result?
A technology that would eventually become the foundation of the modern scuba regulator was developed by a relatively small Australian company without the patent protection that might have secured Eldred's place in history.
In 1960, La Spirotechnique, the French company associated with the Aqua-Lung and owned by Air Liquide, acquired Eldred's business. Eldred worked with the company for a period before eventually leaving the diving industry, disappointed by how things had unfolded. Production of the Porpoise eventually ended, although the Australian Navy continued to receive equipment under an existing contract.
The irony of diving history
Today, most recreational scuba regulators use the basic two-stage, single-hose configuration that Ted Eldred pioneered with the Porpoise.
The equipment in your dive bag may look nothing like the regulator Eldred built in Melbourne more than 70 years ago. Modern regulators use advanced materials, sophisticated balancing systems, environmental sealing, and highly refined engineering.
But the basic concept remains remarkably familiar:
High-pressure air is reduced at the first stage, delivered through a low-pressure hose, and supplied to the diver through a demand valve at the mouth.
That basic architecture traces its roots back to the work of people like Ted Eldred.
So the next time you put your regulator in your mouth and take that first breath underwater, remember the story.
Cousteau and Gagnan helped give the world the Aqua-Lung.
Ted Eldred helped give us the regulator configuration that modern divers use today.
And perhaps the most remarkable part of the story is that Eldred's contribution came from a small workshop in Melbourne, Australia, built by a man who simply wanted to make diving equipment work better.
He succeeded.
More than seven decades later, we're still breathing through his idea.
