Saunas on wheels and water: four operators, four ways to sell the heat

Every so often in Oslo, a sauna casts off. Up to ten people in swimsuits sit around a wood-fired stove while a skipper steers the cabin away from the quay at Aker Brygge, out between the small islands of the fjord. When the bathers are hot enough, they ask the skipper to stop, and they jump into the sea. KOK, the company that runs these cruises, calls them KOKCRUISE. Each one lasts two hours, changing time included. Norway's official tourism site says the tour boats run on electric motors powered by solar panels and glide almost without a sound.

KOK is one of a number of saunas that float or tow. Here are four operators, in Oslo, Brighton, Seattle and Toronto, and what each shows about why a founder might put the heat on wheels, or on a hull, and how each charges for it.

Oslo: the sauna that becomes a boat

KOK began with a team-building trip. Kristin Lorange, then a commercial pilot, tried floating saunas in the Stockholm archipelago. She disliked both saunas and cold water, the company says, but loved the combination. She founded KOK in 2017. The first sauna boat launched at Langkaia, near the Oslo Opera House, in February 2018. Lorange kept flying full-time while pregnant, until five months in. Few people swam in that part of the harbor then, the company recalls, let alone in winter.

KOK now runs nine floating saunas, five at Langkaia and four at Aker Brygge. It sells time in them three ways. A shared session, FELLESKOK, lasts 90 minutes including changing, with up to eight people and a sauna master who helps with wood and water for the stove. A private session, PRIVATKOK, books the whole sauna at the dock for two hours, for up to ten people. And there's the cruise. The company also lists a sauna-club subscription for private sessions, from NOK 150 per person per month, currently marked as coming back. KOK says its Oslo operation received Blue Flag environmental certification in 2025 for the fifth year running.

By KOK's own account, the business has done very well. Turnover doubled every year for three years, reaching NOK 23 million in revenue in 2023. The Oslo operation runs under KOK Norway, which the company describes as the concept owner and franchisor. It names Stockholm, Copenhagen, New York, San Francisco, Tokyo and London as targets.

Being on the water has had at least one unplanned benefit. In February 2024 a Tesla appeared to drive off the quay at Akershusstranda into the fjord. A floating sauna skippered by Nicholay Nordahl pulled the two occupants aboard and let them warm up inside, CBS News reported. The sauna site SaunaTimes identified the boat as one of KOK's.

Brighton: the horsebox that became a spa

In 2018 Liz Watson and Katie Bracher put a sauna in a converted horsebox and parked it on Brighton Beach. It was, according to the British Sauna Society, the first horsebox beach sauna there. A November 2023 Guardian travel roundup called Beach Box "arguably the country's most famous seaside sauna." The company quotes the line on its homepage, without the "arguably."

The trailer did more than look good. In 2022, Brighton and Hove News reported, Beach Box had been trading under the 56-day permitted-development rules for temporary changes of use. It applied for temporary planning permission when it moved a few hundred meters east along the shingle, from a development site to Banjo Groyne. By then it had about 15,000 clients and ten staff.

Today the site has four saunas, and the horsebox is only one of them. Leil, a six-seat converted horsebox built by Beach Box itself, was originally made for the Albion football team, the company says. Löyly, an eight-seat aspen sauna, and Lotta, a nine-seat cedar sauna with panoramic sea views, came from outside sauna makers. A small Lithuanian-style pirtis, for up to three people, is for private hire and treatments only. Around them are cold showers, an ice bath, a plunge pool and the sea.

Its pricing looks like a gym's. Memberships run from £25 a month for three sessions to £70 for ten. Groups book a whole sauna for 90 minutes by buying every seat. A calendar of hosted sessions includes queer, FLINTA, sober and clothing-optional nights. Beach Box started as a horsebox and grew into a four-sauna site at Banjo Groyne.

Seattle: priced like a spin class

Bywater Sauna came out of a cold-water swimming group. Nate Garberich founded the Coldwater Collective in 2023, Seattle magazine reported, after putting out a call online for people to join his year-round cold plunges around Seattle. He hauls the sauna to as many meetups as permits allow. In July 2024 the neighborhood site My Ballard reported that Bywater's 20-foot portable barrel sauna was parking at Golden Gardens beach on Fridays and Saturdays and at Alki on Sundays, at $35 for a 60-minute session. Seattle Met describes Bywater's barrels as Minnesota-built, with twin wood fireplaces and room for 16.

The business model is the most transparent of the four. Sessions run 60 or 75 minutes and are booked by the seat, like a workout class, as the company itself puts it. They cost $35 on weekdays and $40 on weekends. Members pay $100 a month for unlimited sessions, capped at one a day with two upcoming bookings at a time, plus a guest pass. A group that wants the sauna to itself pays for every seat; the company's own example is $640 for a 16-seater at $40 a seat. Its locations are Alki Beach, Golden Gardens, a seasonal dock on Lake Washington and, from October to June, the beer garden of Old Stove Brewing in Ballard.

One line on Bywater's group-booking page explains much of mobile sauna economics. Availability "largely depends on park permit availability." The trailer is what lets a sauna use public waterfront at all. It can arrive for a permitted session and leave when the permit ends.

Toronto: a tornado, a tool shed, and pay-what-you-can

The most unlikely origin story belongs to Sedar Sauna. In July 2022 a tornado hit Havelock, Ontario, and threw a mobile tool shed at Matt van Steenburgh's family cottage 100 feet over a tree line, The Globe and Mail reported. The shed was wrecked, but its trailer still rolled. Van Steenburgh, a home builder, started rebuilding it in October 2023 as a Finnish-style sauna. He used white cedar grown and milled in Ontario and a wood-fired stove. Its first outing was Toronto's New Year's Day polar bear dip in 2024.

With his friend Jason Wong, who heads a marketing consultancy, van Steenburgh opened it to the public, first through a WhatsApp group and then online booking. By spring 2025, the Globe reported, the black ten-person sauna parked in the Beaches, in the city's east end, every Saturday, and at a lakeside spot in the west end one Sunday a month. Hour-long sessions were pay-what-you-can, and more than 850 reservations had been made in three months. "There's an excitement about doing the tough thing," Wong told the paper. The pair had asked the city to extend into winter a permit system it already ran from May to October for kayak and paddleboard businesses.

Sedar's old web address now leads to Kotisauna, a community sauna at Evergreen Brick Works. It calls itself a social enterprise and a pilot for sauna as public infrastructure. Community sessions start at $30, and a private session for up to 16 costs $300. Whether it is the same trailer, and the same team, the site doesn't say. The model has changed. The idea, sauna as a cheap weekly habit rather than a spa day, has not.

What the wheels buy

Four operators are not a trend line. But taken together, they suggest that a mobile sauna is often a way to sit on valuable waterfront without owning or leasing it. Beach Box traded under temporary-use rules before seeking planning permission. Bywater's schedule follows its park permits. Sedar's founders asked Toronto for a winter permit. KOK simply floats. Its saunas sit in Oslo's harbor, not on land.

They also show how small the unit of sale is. A sauna here seats between two and sixteen people, so every operator here sells seats, by the hour, by the month or by the whole cabin. Their pricing looks more like a fitness studio's than a spa's, and memberships keep the seats full on weekdays.

And for these operators, mobility was a starting point, not the end. Beach Box began with one horsebox and now has a site with four saunas. Sedar's trailer led to a pilot at a fixed venue. KOK went the other way: it started at the quay and made moving a product of its own, the cruise. In each case the wheels or hull made it possible to start, and each now leans on regulars: memberships, subscriptions or community sessions.