Oliver Isler didn’t begin with a product idea. He began with a dream. “More than fifteen years ago,” he said to In Depth Magazine, “I had a beautiful dream in which I was swimming peacefully among whales and dolphins,” he writes, recalling the moment that set everything in motion. When he woke, the thought stayed with him: perhaps with a small, integrated breathing system, a human could move through the ocean with something closer to that same ease.
From that idea came Hydrophilis, a device that looks less like dive gear and more like an attempt to reshape the human body into something hydrodynamic. When I first learned to dive, it was no easy task connecting all the parts of the breathing apparatus. Under the water, it never really felt like it belonged to me. Could this new invention make Scuba diving more accessible and safe?
Related: Are diving trips to the Rea Sea safe?
The problem Oliver is trying to solve is not simply how to breathe underwater. That problem was addressed long ago. The deeper issue is how awkward, noisy, and inefficient humans remain in the water even with modern equipment. Complicated tanks, hoses, and regulators turn the diver into a slow, bubbling machine.
Even advanced rebreathers, while quieter, are still bolted onto the body, creating drag and distance between the diver and the environment. Hydrophilis tries to erase that separation. Isler approached the design as an aerodynamics problem, noting that “the ideal shape for minimum resistance is the National Advisory Committee for Aeronautics (NACA) airfoil,” and he built the entire form around that principle.
The result is a system where the breathing apparatus is not worn but integrated. The rebreather sits on the chest rather than the back, which he chose deliberately “to avoid Immersion Pulmonary Edema (IPE), a dangerous affliction whose risk is higher when inhaling… from a back-mounted counterlung.”
The helmet extends forward in a smooth cone, reducing turbulence, while the body remains close-fitted and free of external weights that would disrupt flow. Even the ballast is hidden in the fabric. Everything is shaped to move water aside rather than fight it.
There is also a philosophical shift here. Traditional dive gear assumes resistance and compensates for it with power and air supply. Hydrophilis assumes that the better solution is to reduce resistance until less effort is needed in the first place. Isler reports that the system allows “reasonably good” speed with minimal effort, especially when paired with a monofin, and that autonomy reaches between 60 and 90 minutes depending on exertion.
That is achieved with a remarkably small system, built around a one-liter tank and a compact rebreather, far removed from the heavy configurations divers are used to.
Still, the project is not finished. Isler has completed a few dozen dives and continues to refine the design, adjusting buoyancy, improving visibility, and solving issues like occasional leakage under certain breathing conditions. There is no commercial version yet (angel funding anyone?), no certification pathway announced, and no clear date when something like this might be available beyond experimental use.
Even he is cautious about its future, writing that “it’s impossible to say whether it will become a model for the future,” though he clearly finds satisfaction in having built something entirely original.
What Hydrophilis does offer, even in its unfinished state, is a different direction. Jacques Cousteau helped free divers from the surface by giving them independent air, but the systems that followed defined the diver as someone carrying life support into an alien world. (Related: we interview Cousteau’s grand-daughter here).
Isler’s work suggests another path, one where the human form adapts to the physics of water instead of overpowering it. The silence of a rebreather, the reduced drag of a continuous shape, the possibility of moving without bubbles or strain, these are not just technical improvements. They change the relationship between diver and ocean.
