GTT 135 (Stefania, one of two hulls)

What is Stefania, and why does Dynamiq call her a flagship?

Stefania launched on 10 February 2021 at Dynamiq's original Massa shipyard on the Tuscan coast, the same facility that built JAABER, and completed sea trials that month under yard captain John Scullard before her delivery to her owners in July 2021, several months later than the early-March handover Dynamiq had initially scheduled. She was the first of two GTT 135 hulls built and, at 41 metres, the largest yacht the yard had delivered at that point, positioned above the smaller GTT 115 line that JAABER represents. Naval architecture came from Van Oossanen, the same Dutch house behind every GTT hull, drawing a fast-displacement platform intended to cross an ocean at a genuine cruising speed rather than just look fast at a boat show.

What sets her apart from every other Dynamiq, and from most yachts afloat, is the finish: a metallic gold hull paired with dark brown accents, a colour scheme Dynamiq's founder Sergei Dobroserdov said was chosen by an owner who wanted something that did not follow the mainstream path most buyers take. Dynamiq's own account credits the choice to a family owner who selected the yacht specifically for her reverse bow, extended waterline and amidships master suite placement, features that set the GTT 135 apart from Dynamiq's earlier hulls as much as her paint job does. The result earned Best Naval Architecture at Boat International's 2022 Design and Innovation Awards and a nomination at the 2022 World Superyacht Awards, an independently judged pair of results reported by both Superyachts.com and Yacht Charter Fleet.

Who actually designed Stefania, and why do the listings disagree about it?

Three independent accounts of Stefania's 2021 launch, Boat International's own sea-trial report, Superyachts.com's launch story and Nautic Magazine's coverage of the reveal, all credit the exterior to Dobroserdov Design and the interior to Giuseppina Arena. That is a different pairing from JAABER, whose exterior and interior both came from Studio F.A. Porsche, and it matters because Boat International's own superyacht-directory entry for Stefania lists Studio F.A. Porsche for both roles instead, a discrepancy inside the same publication that a buyer doing diligence should resolve directly with Dynamiq rather than trust either listing blind. Weighted by source count, Dobroserdov Design and Arena is the better-supported attribution, and it is also the more plausible one: Dynamiq's own flagship, unlike a licensed-collaboration model such as the GTT 115, is the yacht the founder's own studio would be expected to style.

Arena's interior leans into an art deco language rare on a modern fast-displacement hull: 2.2 metre ceilings throughout, a working wood-burning fireplace in the main saloon, custom Fendi Casa furniture, and a gold and dark brown material palette that continues the hull's exterior colour indoors rather than reverting to the white-and-oak default most yards use. The master suite runs the full beam on the lower deck, and the yacht carries a beauty salon in addition to the usual beach club and pool, a genuinely unusual inclusion Yacht Charter Fleet's own specification lists among her amenities. None of that changes the hull beneath it, which is shared engineering with every GTT, but it does mean a prospective buyer comparing Stefania to another GTT 135 should ask which studio actually built the one they are looking at, since Dynamiq has used more than one design team across the range.

Stefania is the one Dynamiq hull with a genuinely public price history: a court-ordered auction that started at 10 million euros in March 2025, a reported final price disputed between 10 and 11.4 million euros and a resale asking price of 14.95 million weeks later, a nearly 5 million euro swing on one boat in a single month.

How fast is Stefania, and how far can she actually go?

Boat International's contemporaneous sea-trial report, filed the same month as her launch, recorded Stefania cruising at 15 knots on 190 litres of fuel an hour and reaching over 20 knots at full throttle, with a quoted range of 3,500 nautical miles. Every account published since gives different numbers: Boat International's own yacht-directory entry lists a 19 knot cruise and 21 knot top speed with a 3,000nm range at 12 knots; the brokerage site RU Yachts states a 16 knot cruise, 21 knot top speed and a 5,000nm range on 29,600 litres of fuel; and Yacht Charter Fleet's specification gives a 12 knot cruise and the same 5,000nm range on roughly 29,000 litres. None of those four sources agree with each other on cruise speed, and the range figure alone spans 3,000 to 5,000 nautical miles depending on which listing is read.

That spread is not necessarily an error on any single source's part. A fast-displacement hull's real-world range depends heavily on which speed it is measured at, and Dynamiq itself may have revised the GTT 135's official figures between 2021 and today's brokerage listings. But it means the only number here that comes with directly reported context, speed and burn rate together from an actual trial, is the original 15 knot, 190 litre-an-hour figure. Unlike JAABER, no source checked for this page describes Stefania as carrying the hybrid electric system Dynamiq fits to its GTT 115 Hybrid; propulsion is conventional twin MAN V12-1650 diesels through straight shafts, without the low-speed electric running JAABER's brochure leads with. Van Oossanen's round-bilge, fast-displacement hull form is otherwise identical in concept to every other GTT.

Why was Stefania seized by French authorities, and what happened at auction?

The Marseille public prosecutor's office alleged Koniukh used fraudulently obtained funds to buy both Stefania and a villa on the French Riviera, and requested Italian financial police arrest the yacht while she was in Genoa in October 2023. AGRASC, the French agency that manages seized and confiscated assets, handed the sale to the auction house De Baecque et Associes; a first auction date of 25 January 2024 was postponed, and the sale was delayed further by a dry-docking period in April 2024 needed to keep her RINA classification current. The sale finally concluded at La Ciotat in France, with a starting price set at 10 million euros against an estimated value of 10 to 12 million euros, reported by France 24 two days ahead of the scheduled 27 March 2025 auction date.

What she actually sold for is not settled across the sources checked for this page. Boat International and the outlet Autoevolution both report a final price at or around the 10 million euro starting bid; Megayacht News, citing the auctioneer De Baecque et Associes directly, reports a private sale concluding two days ahead of the scheduled auction at 11.428 million euros, with the buyer an unnamed client of the Florida brokerage Italian Yacht Group. The auctioneer's statement, as quoted by Megayacht News, noted the twin MAN engines had just 250 hours on them at the time of sale, and that two Seabobs and all interior furnishings were included, real and useful detail for anyone pricing a similar resale even where the headline number itself is disputed. Within weeks of the sale Stefania reappeared on the market through Boat International's own listings at an asking price of 14.95 million euros, well below the roughly 16.5 million euro figure Autoevolution reports as her original build-era valuation.

What is it actually like to be aboard Stefania?

The five-cabin, 10-guest layout (one listing gives an upper range of 12 with the pullman berth used) puts Stefania a notch above JAABER's three-cabin, six-guest GTT 115 configuration, reflecting her position as Dynamiq's larger flagship rather than the smaller hybrid model. The sundeck runs to 120 square metres with a forward jacuzzi, two 75 inch televisions and a bar, while the main deck carries an oversized pool and a dedicated beach club with its own second bar below, genuinely unusual inclusions on a 41 metre yacht, where most builders trade pool and beach club against cabin volume. A 1.8 metre draft, shallow for her length, opens anchorages a deeper-hulled 40 metre could not reach, the same practical advantage Dynamiq built into JAABER's GTT 115.

Six crew look after the ten guests, a reasonably lean ratio for a yacht this size, and the yacht is not currently listed for charter through Yacht Charter Fleet's own directory despite having been offered through the broker Arcon Yachts at her 2021 delivery, consistent with the ownership disruption her 2023 to 2025 seizure and sale created. Whoever owns her today inherits Arena's art deco interior largely intact, per the auctioneer's own note that she sold with all interior furnishings, though a buyer should confirm directly with a current broker whether anything has changed since the 2025 sale, since none of the sources checked for this page describe the yacht post-sale in any detail beyond the listing price.

What does Stefania actually cost today, and what should a buyer check?

That is the opposite problem JAABER presents: where JAABER has essentially no resale data because her owner has never sold, Stefania has an unusually well-documented price history precisely because a court forced the sale, a starting bid of 10 million euros, a reported final price disputed between roughly 10 and 11.4 million euros depending on the outlet and a resale asking price of 14.95 million euros within weeks. A buyer treating any single one of those numbers as the yacht's true market value would be wrong; together they show a swing of nearly 5 million euros in a matter of weeks, which says more about forced-sale pricing than about the GTT 135 as a model.

Running costs, crew wages, insurance and refit history are not published anywhere in the sources checked for this page, consistent with the pattern across Dynamiq's whole range. What is published, unusually, is mechanical condition at the point of sale, 250 hours on both MAN engines as of March 2025, which is a genuinely useful data point for anyone comparing her against a fresh-build GTT 135 at 22 million euros, Dynamiq's current list price for the model. A buyer should also independently confirm which design credits and which performance figures the current owner or broker will stand behind, since Boat International's own archive contains two different design-credit claims and four different range figures for the same yacht.

Who it is for: A buyer drawn to a genuinely one-off gold-hulled flagship with real transatlantic-capable engineering, who is comfortable doing independent diligence on a yacht whose ownership history includes a criminal seizure and a court-ordered sale, and who will verify performance and price figures directly rather than trust any single published listing.