"Unea Grey": Small cruiser made from sauna tree becomes a masterpiece - and a real eye-catcher
Nils Theurer
· 04.01.2026
Spectacular news from Finland: for the first time, no fatal swimming accidents at Juhannus, the midsummer festival there! It was simply too cold - not even heavily inebriated locals went into the water. But a few days later, the first sighting of the "Unea Grey" was already swimming from a frog's perspective.
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"The sauna is already hot enough!" says Jouka Dehm, helping to get the visit off to a very authentic start. The man with a father from Germany and a Finnish mother has moored his boat in front of the "Mökki", the family summer house, on Lake Päijänne. It is the second largest inland body of water in Finland, twice the size of Lake Constance. The huge inland sea connects dozens of fjords, widenings and narrows to form over a thousand square kilometres of sailing area, with the longest one-way trip measuring more than 180 kilometres. The race is always held alternately northwards or southwards as Päijänne-Purjehdus, the largest inland regatta in Finland. This race is Jouka's driving force; he wants to take part in the long distance with his own boat.
Pine trees felled directly behind the sauna
The product of this dream can already be seen through the pine trees between the jetty and the buoy. But first we enter the sauna, which is already heated to 70 degrees. Almost six million people live in Finland - and there are around two million saunas there. The most important manufacturer of sauna heaters produces in Muurame, also on Lake Päijänne, and his holiday home is just around the corner. With a jetty. A Finn without a boat? Unthinkable.
After the first swim, the boat steams into Lake Päijänne, and the first thing you notice when swimming round Jouka's boat is the strikingly vertical transom. Five and a half metres and crawls further along the Scandinavian light-coloured pine hull, there is an equally protruding stem. "I felled the pines directly behind the sauna," says Jouka, explaining the origin of the wood after surfacing. In 2013, he took them a few kilometres away to Kari's sawmill, where they were cut into sawn timber and dried.
Everyone on the shore seems to know each other. And as is usual in Scandinavia, surnames play a subordinate role.
The light-coloured glider fits harmoniously into the scenery. Cast off now? No problem, says Jouka and grabs two fishing rods, wobbler box and landing net; it's calm at the moment - but at least you can fish. So the 1.6-kilowatt Kräutler electric motor is tried out, of which nothing more can be seen in the cockpit than the floor compartment for the two Hoppeke batteries with 66 ampere hours each and the small steel lever on the coaming. "I would even have had a five-horsepower petrol outboard available. But it doesn't suit a boat like this," says Jouka, explaining his choice of engine.
With a discreet click, the twin-wing aircraft on the pod under the hull unfolds with the first revolutions, otherwise nothing disturbs the general silence. At five knots and full speed, the batteries last for an hour, at two knots it's ten. "We don't need to be much faster, otherwise the zander won't bite," says Jouka in a Finnish and cosy way, letting out 25 metres of line with wobbler bait on the port and starboard sides.
A masterpiece as big as possible
In 2013, Jouka began his training as a boat builder in Parainen, at the "Livia Ammattiopisto", a boat building school in south-west Finland on the Baltic Sea. Before that, he went to school in Gelnhausen, studied sociology and English in Freiburg and ran fundraising campaigns for Amnesty International and Greenpeace in Hamburg and Berlin. In Berlin, he helped to refurbish a 1955 Wismar long keeler, but its mast was never erected.
When the school in Parainen was looking for international participants for its course, he immediately realised that this would allow him to combine his regatta dream with his future career aspirations.
In the first year of training, it is customary to produce a boat drawing; in the second, the students build the structure. His fellow students opt for delicate dinghies and motorised boats, he designs and builds as large as possible. The classroom with the table saw determines the length of the boat, with a good six metres of space in front of and behind it. For this reason, his creation is exactly 5.60 metres long.
For the fuselage drawing, he doesn't work his way into design programmes, he moulds it to a scale of 1:10 from floral clay. "I used to work as an event manager, so we did a lot with the green stuff. I glued a few blocks together for the hull." He first trims the block with a knife and then presses his desired hull with his thumb and the ball of his hand until the proportions seem right. "I cut the model into 14 equally long pieces with the knife and outlined them on drawing paper."
Enlarged sections are used to create 13 laminated half frames. In his second year at the boatbuilding school, he uses them to erect an overhead frame. However, it turns out that the test mouldings applied to some of the frames are not strong enough. The eye-catching slender foredeck is intentional, but in the first frame version it would break the mouldings. He reworks the formers in these places.
Design of cabin and cockpit after construction of the hull
After accurately sawing the sauna tree into six metre long slats, he mills a convex and a concave profile into each of them; this allows them to nestle together without additional planing. As a special feature, he screws each moulding to its neighbour when gluing with epoxy. Only two of the more than 2,000 screws are revealed when the boat is later smoothed. Starting with the coaming and the keelson, the actual hull is soon completed. It is initially completed with a deck made of birch plywood. On the advice of his instructor, the coaming is given a negative crack so that the transom does not protrude even more. To do this, Jouka saws off the hull, sloping aft.
Only now is he starting to design the cockpit and cabin: "I made several drawings and then realised them as proportionally as possible with MDF panels." The flat superstructure ducks down on the otherwise high-sided hull and provides a visually appealing balance. The roof, reminiscent of cat boats from the American east coast, is slightly curved both lengthways and crossways. Jouka covers it with waterproof and impregnated tarpaulin, a traditional, functional and particularly suitable design here.
"I'll tell you how the deck and mast were made on the way." There was nothing on the hook on the first trip, but now the westerly current promises 2 to 3 Beaufort in T-shirt weather, in other words a sunny Finnish summer of sailing.
Football and fish
Jouka grabs a blanket, four beer cans and the fish pan. A waterproof tablet also comes on board - presumably for navigation, as there is a lurking collection of granite reefs next to the 1886 islands that are still just visible: "No, for football!" Finally, the network coverage is excellent, some of the tallest trees on the wooded horizon can be recognised as mobile phone masts on closer inspection.
At the kick-off, we enter the fairway, which is perfectly marked by spars and bearing lines. The narrow passage to Lake Ristinselkä opens up at half-time. For the second half of the race, a cross is on the cards, but the headsail luff lacks power. Only after it is lowered and the splice of the Dyneema jib halyard is fastened with a toggle to save space does the initial tacking angle of 120 degrees drop by 10 to 15 degrees. The transom dives deep and creates a powerful whirlpool, which slows you down considerably, especially in light winds. "It doesn't matter - we can't be that fast for our zander anyway." There is also an astonishingly eager appetite.
The mainsail will be responsible for this. "My teacher told me: 'Jouka, you're still learning to sail; cut a metre off the original mast'." That's what he did, what a shame! The mast itself is a piece of jewellery. Only three metre long Douglas fir planks were available. The journeyman cut them to the length of the mast and sawed two 30-degree flanks. On a mast bench with specially made supports, he glues the slats together to form a drop-shaped hollow spar.
Back and forth in the mast construction phase
A higher mast was actually planned. In addition, the local sailmaker - Jouka wants to emphasise the regional aspect in particular - refuses to implement the radical spreader batten that was actually planned. In addition, the strong pull on the jib halyard relativises the already discreet mast drop, all factors shifting the lateral point forwards. "The ship will never be finished!" comments Jouka. The next steps will therefore include putting the mast on deck with a folding mast foot to lengthen it again and rigging a new mainsail with a fathead.
During the mast construction phase, his father, a mechanical engineer, and a pensioner friend of his join in. The project has already swallowed up a five-figure sum, although partners and sponsors have been found for some of the equipment. To keep the costs in check, Jouka buys top lights, shroud tensioners, rudder fittings and electrical switches on eBay - ready-made mast and boom fittings do not fit into the budget.
"The two of them really got to grips with this task. The three-millimetre-thick stainless steel hull is certainly made to last." The gift was also sandblasted to give it a matt finish that harmonises perfectly with the finished boat. He made the deck from Douglas fir poles and painted them.
In the meantime, the two years at the boatbuilding school are over and Jouka works for a year at the shipyard of renowned wooden boat refitter Janne Peterson in Helsinki. He then spent another year at the boatbuilding school and completed his master's degree. Since then, he has found it easy to lay bar decks. His boat is his Mestarityö, his masterpiece.
In addition to financial support, his mother now also wants to make her contribution to the boat, and a long search was made for a suitable task for her. "I then noticed that shroud tensioners are always solid aluminium parts or ugly plastic ones. Now I have the cheapest solution with pieces of plastic tubing, for which my mum knitted me brown and grey protectors from robust hemp wool."
Sea dwarf with magnificent speed
The destination of the cruise, the island of Sudensaari, four football pitches in size, has three buoys, two rubbish bins and an outhouse. The rubbish bin and compost toilet are emptied by a weekly service boat. It is unusual that there is no sweat lodge here, "the local clubs usually look after several islands and also bring firewood to the saunas," says Jouka, explaining the local customs.
He draws the water for the potatoes from the lake using a pot, "it's Helsinki's drinking water reservoir". As the sun sets at 11.30 p.m., they head for the sufficiently large bunks to the left and right of the oak sword, and the heat of the sun wakes them up for the first time at three in the morning.
When sailing backwards, "Unea Grey" runs up to 6.2 knots with Schrick in the sheets, at times the stern swirl tears off the transom and fires up the speed, which is already magnificent for this sea dwarf. The remarkably wide waterline makes the hull extremely stiff. With the slight heel, the expected upwind yaw also materialises. "It's not going to be a zander now. But at this speed, we might catch a lake trout, which is just as good," says Jouka, making friends with the speed. But nothing bites.
Chance gives the boat its name
"I actually wanted to name the boat after my grandmother Anna Maria," says Jouka, explaining how the name on the transom came about. "Then, for the sake of brevity, it became the other grandmother Aune and later Aune Grey, based on the colour of the cockpit." A friend milled the brass letters for him, just as family and friends contributed greatly to the overall project. "When I fitted them, it wasn't right at all, the A was too far to the left. But re-drilling everything again and living with a rear end full of plugs?" He decides to just move the first letter. "Since then, the boat has been called Unea Grey. Unea is a volcanic island in the Bismarck Archipelago, which fits."
Unea Grey was originally due to take part in the long-distance regatta for the first time in 2015, but this did not materialise as completion was delayed until this year. Jouka counts 1500 hours working on the boat. In the meantime, however, time is short, as he now works as a wooden boat builder with a workshop trolley. Now, for example, he is returning from refitting the stern of a historic 13 metre long "Vessibussi" (water bus) from Lapland.
The typically taciturn Kari comes to visit the Mökki, he had wood to deliver anyway and wanted to see what had become of the maritime pine he had sawn up five years earlier: "Kyllä se on nätti" - that's pretty. An email from Jouka days later: "I pulled the zander out of the water at the weekend with my godfather Simo."
Technical data of the "Unea Grey"
- Length: 5,40 m
- Width: 2,05 m
- Depth: 1,00 m
- Displacement: 750 kg
- sail area: 17 m²
- Costs for material: 15.000 €
