Sublio, the “24-carat” water: our team took the plunge at La Ferme d’Augustin in Ramatuelle

From 4 to 6 October 2026, our editorial team checked in at La Ferme d’Augustin, in Ramatuelle, with a simple brief: to swim in the Sublio pool and report back on the experience. A “24-carat” water dreamt up by Frédéric Esnault, a pool heated to 30 °C beneath the umbrella pines, and an inventor who welcomed us at the water’s edge.

☰Contents

1. Arriving at a pool heated to 30 °C
2. Monday, 9 am, a pool still deserted
3. Frédéric Esnault, from the Restonica to Sublio
4. “A truly different sensation”
5. The reactor, the patent and twelve studies
6. Where to try it in Ramatuelle

Arriving at a pool heated to 30 °C

Before setting off, our editorial team summed up its mission on camera: an innovative pool, Sublio, “which claims to care for the skin”, and a clear job, “to live it, film it and tell you everything, the good and the not so good”. On Sunday 4 October, early in the afternoon, we put down our bags at La Ferme d’Augustin, on the Saint-Tropez peninsula, with one question in mind: “Let’s find out the truth: what is it really like?”

At the hotel entrance, a sign sets the tone: “pool heated to 30°”. The pool itself lies a little further on, among umbrella pines, striped loungers and Anduze jars. By the water, the Sublio reactor is hard to miss: a lacquered blue casing ringed with gold bands, mounted on stainless steel legs, beneath an information panel in four languages. First impression: an installation proudly presented as a design object, rather than hidden away in a plant room. The sign of a house that fully believes in its equipment.

Monday, 9 am, a pool still deserted

The next day, Monday 5 October, we are at the poolside by 9 am. The sky is grey, the loungers still empty, and the water is so clear you can make out the grid of the mosaic on the bottom. On camera, we keep a tester’s distance: “They say this water cares for the skin. Let’s see.”

First dive, first finding: the water feels silkier to the touch, an impression that returns with every swim during the stay. We linger far longer than planned, without looking at our watch.

The swim follows the rhythm of the equipment: five power jets, a jet stream and a blower, plus a swan-neck cascade shower that falls into a white swirl of bubbles, next to a jar planted with a citrus tree. At 30 °C, the water invites you to stay in longer, and the jets turn the pool into a true relaxation circuit, neck under the cascade, back against the jets.

Frédéric Esnault, from the Restonica to Sublio

It was beside this pool that Frédéric Esnault welcomed us, to introduce us to Sublio up close. “It was a real pleasure to welcome you and to share with you, in such a direct and personal way, the essence of what I have created,” the inventor wrote to us. In front of the reactor, he takes the time to explain, with an inventor’s undimmed passion, the path of the water and the idea that has driven him for more than thirty years.

Frédéric Esnault dates the start of his story to 1993, in the Restonica valley, in Corsica, where he says he was struck by the effect of the mountain stream’s water on the skin. Nearly twenty years of research followed, between Corsica, Morocco and several French laboratories, leading to the creation of Sublio France in 2019, in the Vendée.

“At first, I spoke of a ‘water sublimator’,” Frédéric Esnault told us. “The term wasn’t used in its strict physical sense; it expressed a much simpler and more ambitious intuition: not merely to treat water, but to bring a different water into being.” The name was then refined: “sublimateur d’eau, then Sublim’eau, then Subli + eau, until it became Sublio”, eau being the French word for water. The final “O”, he says, keeps “an immediate link with water”, while giving the name “a purer, more international and more timeless identity”.

From this same vision came one of the brand’s first slogans, “24-Carat Water”: “not simply improved water, but a new water, precious by nature, conceived as an exceptional material in its own right”. A conviction that runs through the whole conversation, and one that makes more sense once you are in the water.

“A truly different sensation”

On Tuesday 6 October, late in the morning, a few hours before leaving the hotel, we filmed ourselves one last time by the pool: “I’ve been using the pool a lot for several days now, and I can say it: the sensation is truly different.” Different how? A softer, more enveloping water than in a conventional pool, from which you emerge with supple, almost moisturised skin, to the point of doing without cream, which the studies carried out for the brand confirm on the laboratory side.

Three days later, when taking stock, our editorial team ranked the pool among the three things it enjoyed most during the stay: “the most memorable part of the experience”, the one “that truly sets the hotel apart”. And the feeling on leaving the water is clear: “There’s a sensation of softness, no need for cream or moisturiser afterwards.”

For our editorial team, the experience is wholeheartedly approved. Several swims during the stay, in the calm of the morning and then at the end of the day, and always the same pleasure in the water. Sublio is one of those rare innovations that genuinely change the way you experience a hotel: you no longer come just to swim, you come to take care of yourself.

The reactor, the patent and twelve studies

The technical data and study results below are those provided by Sublio. The reactor is fitted to existing pipework, for pools, showers or baths. The water flows through it between inductive plates that act on the electrical charge of the dissolved minerals, without adding or removing anything: this is “Hyperionisation”. In the pool, it works alongside the usual filtration and treatment.

French patent FR3129082, granted to Frédéric Esnault on 14 March 2025, describes water whose “zeta potential”, the measure of this charge, shifts for example from -18.3 to -13.8 mV. An analysis commissioned from Eurofins in 2024 found no significant change in the composition of the treated water. The Sublio Light has also been registered as a Class I medical device in the European EUDAMED database since October 2025.

Twelve studies were carried out for the brand between 2019 and 2025, mostly in the laboratory, on skin samples. The most recent, in February 2025, followed 20 volunteers over four days: improved skin hydration and barrier function, and 95% of participants found the water pleasant.

Where to try it in Ramatuelle

The Sublio pool at La Ferme d’Augustin is reserved for hotel guests, at a 4-star property with 46 rooms and suites, a five-minute walk from the beach, on the Saint-Tropez peninsula. Heated to 30 °C, the pool is open from 8 am to 8 pm during the season, from late April to mid-October. To extend your getaway, discover our selection of spa hotels in Provence.

Article produced in partnership with Sublio, during a press trip to La Ferme d’Augustin, from 4 to 6 October 2026.