Sirena's first steel superyacht, a 42m, sold on spec before launch

A production yard steps up to steel

The 42M is a clean break from the composite motoryachts that made Sirena's name. She measures 42.2 metres with an 8.8-metre beam and a 2.5-metre draft, comes in at 433 gross tonnes, and pairs a steel hull with an aluminium superstructure. Construction began on spec in 2024, and the yard christened this first hull with her owners this week, about two months before her international premiere.

The naval architecture is by Van Oossanen, using its Fast Displacement Hull Form with a Hull Vane foil aft, the same efficiency package that has gone under a run of larger custom yachts. Luca Vallebona drew the exterior, Hot Lab handled the interior, and the layout runs to ten guests in five staterooms.

Why the owner cares

For anyone tracking Sirena as a brand, the point is that it now competes where the full-custom yards do, not just against other production lines. A steel 42-metre carries a different survey, a different flag conversation and a different resale pool than a 30-metre composite, and it puts Sirena's badge on a boat an established owner can step up into rather than out of.

That the hull sold before launch, arranged in-house, is the harder signal. Spec-built steel in the low-40-metre range only gets ordered when a yard is confident a buyer is waiting, and one was. The commercial line from Sirena is that the sale came out of an existing client relationship, which points to a repeat owner trading up inside the range.

The efficiency angle

The Hull Vane is a fixed foil across the stern that recovers energy from the yacht's own wake, and Van Oossanen has spent years claiming double-digit fuel savings from it on displacement hulls. On a 433-tonne yacht that translates into range and running cost, the two numbers a private owner actually feels on a long passage.

Sirena has not published a range figure yet, and the propulsion package is still under wraps ahead of the debut. What is on the record is the intent: a first steel flagship aimed squarely at owners who want a bigger, quieter, longer-legged boat without leaving a builder they already know.

What a composite builder gains by working in steel

Sirena's composite range hits a structural ceiling near 40 metres, not a styling one, and the 42m is the first hull built to clear it with a fast-displacement steel hull under an aluminium superstructure.

Sirena's chief commercial officer Ali Onger has put the ceiling plainly: below 40 metres the yard builds in GRP, which has restrictions no amount of tooling refinement removes. Past that length the resin and mould economics stop paying for themselves, and the structure has to work harder than a composite layup can manage. Steel and aluminium answer that the way most of the industry already does, a steel hull for strength low in the vessel and an aluminium superstructure to keep weight off the top, preserving stability and speed. The 42m carries the logic into its naval architecture too. Van Oossanen's fast displacement hull form is tuned for efficient long-range cruising rather than raw speed, and the class numbers back it up: RINA classification, 434 gross tons, a range of 4,000 nautical miles at 10 knots, and a top speed of 15.5 knots from twin MAN diesels rated at 1,450hp each.

The 42m is not a one-off. Sirena unveiled a three-boat steel and aluminium line, 35, 42 and 50 metres, back in 2022, building the 42m first as the entry point rather than the biggest hull it could manage. Eureka Yachts handled the engineering, and construction ran through Sirena's Istanbul yard. CEO Cagin Genc said the yard brought in an external surveyor to monitor the build, a response, in his words, to the complexity of the build on a material Sirena had not worked in at this scale before. That is a tell: a builder confident in its own composite process still wanted an outside check on steel. The strategy matters as much as the engineering. Sirena's composite range already runs from 48 to 118 feet, capped by the newly launched Sirena 118, and the steel line starts underneath that ceiling, meant to grow toward the 50m rather than replace the composite boats.

What the undisclosed sale and a sister hull's price sheet reveal

Sirena has not named the buyer, but the process around the sale, and a second hull's public asking price, sketch the commercial logic behind selling a superyacht before her launch.

Sirena has not named the buyer. Megayacht News, citing the builder, describes the deal only as an in-house sale, possibly to an existing Sirena owner, with the yard declining to say more. What is public is the process, not the person: construction started in the Istanbul yard, though Boat International dates it to 2023 and Megayacht News puts it a year later, in 2024, a discrepancy neither outlet has resolved. The yacht launched in July 2026, roughly two months ahead of her Monaco debut, and Genc credited the schedule to the outside surveyor, saying the yard was exactly where it wanted to be at this stage, on schedule and working to a very high standard of finish. A second 42m hull is listed through Ocean Independence at EUR 23,950,000 for 2026 delivery, the clearest public price signal on a yacht whose sold hull carries none.

The natural comparison is the Sirena 118, the 36 metre composite flagship launching the same season and, like the 42m, already sold before her public debut, to a repeat client rather than a first-time Sirena owner. Onger called the 42m sale a natural evolution of the brand and confirmation that Sirena's approach to building modern, highly capable superyachts resonates with experienced owners, language that fits the 118 just as well. The two boats bracket the yard's 20th anniversary expansion from opposite ends, the 118 pushing GRP as far as Sirena will take composite construction, the 42m opening a steel and aluminium range underneath it. Both sold to buyers the yard will not name, which points to the yard's own owner base, rather than new market discovery, as what absorbs its largest, newest yachts.