Over its 40-year history, Heesen has developed a reputation for building cutting-edge superyachts that have pushed boundaries in design, speed and efficiency. From record-breakers such as Octopussy to more recent innovators such as Galactica Star, Galactica Supernova and Home, Heesen’s facility in Oss continues to play host to remarkable superyacht projects.
The latest project to draw on this extraordinary heritage is Cosmos, an 80.7 metre aluminium superyacht that is set to push the boundaries even further. With a designed top speed close to 30 knots and an efficient cruising speed in excess of 20 knots, Cosmos will use a development of the Fast Displacement Hull Form (FDHF) coupled with innovative construction and advanced propulsion solutions to set new standards for large aluminium yachts. Although the keel-laying ceremony is due to take place later this year in May, this is not the start of the project – indeed, an extraordinary amount of design and testing has already been undertaken and completed.
The proof-of-concept and testing process has comprised several stages, starting with the base naval architecture of the vessel and its hull form, progressing through extensive computational fluid dynamics (CFD) work and physical tank testing of a scale model, and culminating with the design of the propellers and rudder system. For these aspects, Heesen has drawn not only on the expertise of its in-house design and engineering department but also that of long-standing partners Van Oossanen Naval Architects, and propulsion specialists at Rolls-Royce.
The first stage was to develop the FDHF concept and ensure not only that Cosmos benefitted from the efficiency and speed gains of the design, but also that the yacht could retain inherent stiffness – a challenge because Cosmos features all-aluminium construction in order to achieve the client’s desired maximum speed of close to 30 knots. The solution was for Heesen to develop the Backbone® – a method of construction that could deliver the required stiffness in the yacht without adding weight that would have impacted on the yacht’s performance. Such has been the success of the design that the Backbone® has now been patented.
A 3.7m scale segmented model of the yacht was built to use in physical tank tests at the Wolfson Unit in Southampton. After initial data on hydrodynamics, resistance and speed had been gathered, the model has been radio-controlled and self-propelled in order to measure the various bending forces acting within the hull and to prove the Backbone® concept. That provided valuable data for fine-tuning the structural design and to further optimise the construction method.
For such a large aluminium yacht, it is particularly important to know the real forces created by the sea on the hull, not just to meet Lloyd’s Register requirements but to exceed those and construct the boat to the highest loads that could be encountered.
Using the FDHF design and the Backbone® for such a large aluminium yacht requires a slightly deeper keel depth, but this actually brings further benefits. Due to the slightly increased draft Project Cosmos has a very low block coefficient, which means that the underwater body is very slim with nice verticals in the aft ship area, for an optimal flow of water towards the propellers. This results not only in improved performance but also in higher efficiency, ensuring fast cruising with comparatively low fuel consumption.
Refining the propeller design is the ongoing job of research and design engineers at Rolls-Royce. Alongside the propeller design itself, the Promas system – where propeller and rudder are integrated into a single unit to optimise hydrodynamic efficiency – has been implemented in the design.
Rolls-Royce engineers started by gathering CFD information of the water flow towards the propeller. Then the design process began with Rolls-Royce proprietary software: different iterations of propeller and rudder design were tried before arriving at the optimal solution, which was then tested in physical experiments.
By creating a 1:11 scale model of the Promas rudder and propeller in the test tank facilities of the Rolls-Royce Hydrodynamic Research Centre (HRC) in Kristinehamn, Sweden, the propeller design was fine-tuned not only to ensure the speed and efficiency requirements are met, but also that any potential problems with cavitation can be eliminated. Cavitation is essentially where air bubbles form in the flow of water around and behind the propeller. It is particularly challenging at high speed, and as well as affecting performance it can also have severe impacts on noise and vibration – a critical consideration for any superyacht project, especially for one close to 30 knots! Cavitation issues were identified and eliminated by adjusting the rudder design. Finally, the tests proved that the propeller performed above expectations.
Project Cosmos will feature variable pitch propellers that will enable the yacht to handle both impressive cruising speeds in excess of 20 knots, as well as reaching a maximum speed close to 30 knots – a considerable achievement for an 80-metre superyacht. With the hull design optimised, the construction engineering finalised and the propulsion system going through the last stages of testing, Cosmos is already proving a milestone project for Heesen and the teams involved.
“Project Cosmos is raising the bar once again not only for Heesen, but for custom aluminium yacht building in general,” says Arthur Brouwer, CEO of Heesen. “Both from a technical standpoint and from a performance point of view we are pushing boundaries. Not only has this 80.7m project been designed to reach close to 30 knots, she has been designed for fast, 20+ knots cruising in an efficient manner. The solutions we have implemented to meet all these requirements are once again driving superyachting forward – just as Heesen has done with innovative and ground-breaking projects throughout its 40-year history.”
Following its successful American debut, the Seadeck 7 has arrived in APAC for its regional première at the upcoming Singapore Yachting Festival, running from April 10th to 13th, 2025. Joining the Seadeck 7 on display will be the Magellano 60 and the Grande Trideck.Seadeck 7This year marks a pivotal moment for Azimut in Asia, a region teeming with growth opportunities for the yachting industry. The Shipyard is intensifying its presence locally with a strategic development plan focused on enhancing its distribution network and owner-centric services. Celebrating this expansion, Azimut will host its inaugural Azimut Asian Rendez-Vous in Tokyo during the spring season.Azimut’s dominance in the region is evident in its sales of yachts measuring up to 40 meters, reinforced recently by accolades at the 2025 Best of the Best Awards by the Hurun Research Institute. Recognized as the brand with the strongest appeal among Chinese HNWIs, Azimut also saw the Seadeck 7 honored as the Luxury Hybrid Yacht Best New Arrival.Grande TrideckThis winning streak culminates in Azimut’s participation at the Singapore Yachting Festival, where visitors at ONE°15 Marina, Sentosa Cove, will have the chance to explore the Seadeck 7. Designed to offer a gentler and more sustainable way of enjoying the ocean, the Seadeck 7 integrates cutting-edge technology, design innovation, and a deep commitment to human and environmental well-being. Alongside the Seadeck 7, the Magellano 60, introduced last year, and the Grande Trideck, with two deliveries in the region and a third imminent, continue to resonate strongly with the growing superyacht market.Enrico Chiaussa, Azimut’s Chief Commercial Officer for EMEA-APAC, emphasized, “The Singapore Yachting Festival is the perfect platform to showcase the Seadeck 7, embodying Azimut’s vision of reinventing life onboard through groundbreaking layouts and partnerships with globally acclaimed designers. Asia, with its dynamic energy and burgeoning interest in sustainable solutions, aligns perfectly with our philosophy, making it a vital market for our continued growth.”The Seadeck 7 stands out as the world’s first yacht to merge hybrid propulsion with the Volvo Penta IPS system, leveraging Volvo Penta’s pioneering hybrid-electric technology. Coupled with extensive carbon fiber usage and an efficient hull co-developed by NAMES and the Azimut|Benetti Group R&D Department, this innovation reduces CO₂ emissions by up to 40%, reflecting Azimut’s ongoing pursuit of sustainability.Magellano 60At the heart of the Seadeck Series’ design is the innovative Fun Island – a reinterpretation of the aft cockpit conceptualized by Alberto Mancini. Transforming this space into a sea-embracing terrace, the Fun Island eliminates barriers between occupants and the surrounding marine environment, fostering a profound connection with nature. This ethos carries over into the interior, where Matteo Thun & Antonio Rodriguez employed natural, recycled, and recyclable materials to create a distinctive aesthetic.Azimut Yachts is an Azimut Benetti Group brand. With its Atlantis, Magellano Flybridge, S, Verve and Grande collections, Azimut offers the widest range of 10 to 40 meters.Credits: Azimut Yachts
April 4, 2025
The Italian Sea Group has announced that the outfitting of the much-anticipated Admiral 73m megayacht is in full swing at their headquarters in Marina di Carrara. As part of the esteemed ADM Fleet, which comprises vessels ranging from 66 to 73 meters, the Admiral 73 represents the epitome of luxury and performance. To date, seven units of the fleet have already been sold.The Admiral 73 exterior, masterfully crafted by The Italian Sea Group Centro Stile, combines elegance with modern aesthetics, while the interior, meticulously curated by FM Architettura, exudes sophistication and refinement. During the current outfitting phase, the focus lies on integrating state-of-the-art technological systems and navigation equipment, ensuring that the megayacht remains at the forefront of innovation.Spanning three lavish decks, the Admiral 73 is an oasis of comfort and opulence, tailored to provide an unrivaled entertainment experience for the owner, their family, and guests alike. From its striking design elements to its carefully selected amenities, every inch of the megayacht radiates exclusivity.Large windows on the main and upper decks flood the interior with natural light, framing breathtaking panoramas. The main deck features a wide salon and dining area, blending effortlessly with the outdoor lounge through large sliding glass panels. Foldable balconies and a full-beam indoor-outdoor space further enhance the alfresco lifestyle. An intimate relaxation area at the upper deck completed with a cocktail bar and floor-to-ceiling windows, invites guests to unwind in style.Spacious owner’s suite occupying over 90 square meters on the main deck, the owner’s suite offers unparalleled privacy. Twelve guest cabins and twenty crew quarters, including the captain’s cabin, ensure utmost comfort for everyone aboard.The beach club on the lower deck boasts foldable balconies, complemented by a gym, sauna, and massage room, providing the ultimate retreat for health and wellness enthusiasts. The sun deck is a haven for relaxation, featuring a sun bar, pool, and ample lounging areas for socializing under the open sky.Powered by two CAT 3512C engines, each generating 1500 kW at 1600 RPM, the Admiral 73 delivers a maximum speed of 15 knots and a range of 6000 nautical miles at 10 knots.The Admiral 73 megayacht is scheduled to delivery in late 2026.The Italian Sea Group is a global operator in the luxury yachting industry, listed on Euronext Milan (“EXM”) and active in the construction and refit of motor yachts and sailing yachts up to 140 meters. The Company, led by Italian entrepreneur Giovanni Costantino, operates on the market with the brands Admiral, renown for elegant and prestigious yachts, Tecnomar, Perini Navi, and Picchiotti; the Company has a business unit, NCA Refit, that manages the maintenance and refit services for yachts and mega yachts with a length over 60 meters. Credit: The Italian Sea Group
April 4, 2025
The construction of the innovative Sialia 45 yacht at the shipyard in Poland is proceeding according to plan. A major achievement has been marked with the completion of the hull and deck. The first fully electric Sialia 45 is expected to be unveiled in June, with its official debut taking place at the Cannes Yachting Festival in September 2025. With its advanced battery system, the yacht boasts a range of 55 nautical miles at 25 knots using standard batteries, while the endurance pack extends this range to over 130 nautical miles. Furthermore, it features rapid charging, allowing the batteries to reach 90% capacity from 10% in just over 2.5 hours.As work progresses on the Sialia 45, the hull and deck have been successfully finished, and the bottom liner is nearing completion, signifying a crucial phase in the production process. One standout feature is the use of cutting-edge carbon technology in constructing the hull. Employing three distinct infusion techniques, the lightweight yet durable carbon-fiber composite achieves optimal performance and longevity. The full carbon sandwich epoxy construction ensures structural integrity and minimizes noise and vibrations, delivering a smooth and comfortable experience.With the target completion date set for late June, Sialia Yachts is confident about meeting their production goals. Once the first unit is delivered, manufacturing will ramp up to produce an impressive ten vessels annually. According to Milvio Ricci, Chief Commercial Officer at Sialia Yachts, this meticulous approach reflects the company's commitment to quality and attention to detail.The Sialia 45 promises unmatched power and efficiency. Powered by dual 300 kW motors, the 14-meter electric cruiser can attain speeds of up to 43 knots. Featuring top-tier amenities, spacious interiors, and versatile deck designs, the yacht is designed for extended journeys without compromising speed. Using the standard 500 kWh battery pack, the Sialia 45 can travel 55 nautical miles at 25 knots, while the optional 200 kWh endurance pack increases this range to 77 miles.For even greater flexibility, the yacht can be equipped with either a 140 kW or 350 kW biodiesel range extender, extending the range to 164 or 240 nautical miles, respectively. Fast-charging capabilities ensure minimal downtime, enabling users to quickly recharge the batteries from 10% to 90% within 3.5 hours—even with the enhanced endurance pack installed.Offered in three distinct models – Runabout, Sport, and Weekender – the Sialia 45 caters to diverse needs. The Runabout model incorporates a sleek, low-profile windshield and open deck layout inspired by traditional motorboats. Meanwhile, the Sport variant adopts a center console configuration with a protective windscreen and roof, offering shelter from the elements. The Weekender version features a glass deckhouse that can transform into a climate-controlled indoor-outdoor space, perfect for warmer or cooler climates.Each model boasts a well-designed lower deck, including a full-spec bathroom with a shower and an optional galley or salon area. Multiple seating arrangements, expansive sun pads, and customizable finishes allow owners to tailor their yacht to suit their preferences, whether they seek a functional pleasure craft or a luxurious superyacht.Sialia Yachts prioritizes sustainability across every aspect of design and production. Beyond the eco-friendly electric drivetrain, the company utilizes recycled materials such as cork flooring and emphasizes lifecycle considerations. These measures reduce environmental impact while ensuring high-quality craftsmanship. Additionally, the electric motors require minimal maintenance, eliminating the need for frequent oil changes or servicing typically associated with combustion engines. Batteries are rated for 30,000 cycles and come with a five-year warranty, ensuring reliability and peace of mind for owners.Established in 2017, Sialia Yachts, owned by Silent Straits, is a company focused on sustainability and ocean-friendly innovation aiming to set new standards in yachting, with designs that inspire both enthusiasts and experts. The company offers the following models: 45, 59, and 80 Explorer. Sialia Yachts is based in Warsaw, Poland, with a team that includes members in the Netherlands and Italy.Credits: Sialia Yachts
April 4, 2025
On March 30th, Sunreef Yachts made a significant stride in its global expansion by inaugurating the Sunreef Lounge in Shanghai. Strategically situated at the prestigious Sunch Yacht Club in Pudong, this new facility symbolizes the company's dedication to advancing luxury yachting in Asia.More than just an exhibition space, the Sunreef Lounge acts as a cultural center, facilitating meaningful interactions between clients, collaborators, and enthusiasts. Here, visitors can explore Sunreef's state-of-the-art technologies and environmentally conscious solutions in a refined and engaging atmosphere.Central to the lounge's offerings is the groundbreaking Sunreef Ultima line, which integrates speed, comfort, and sustainability. Designed to inspire responsible ownership, this cutting-edge collection highlights the shipyard's commitment to shaping the future of eco-conscious yachting.By merging global luxury standards with local customs and sustainability principles, Sunreef Yachts establishes itself as a trailblazer in the Asian market. This initiative marks a promising era for the brand and sets a new benchmark for the evolution of yachting in the region.Sunreef Yachts was founded by Francis Lapp in 2002 in Gdansk, Poland. Since then, the shipyard has been designing and manufacturing luxury sailing and power multihulls. Credits: Sunreef Yachts; rleine/unsplash.com
April 3, 2025
Northrop & Johnson announces the successful sale of the 51-meter Sapphire, a Trinity-built motor yacht, through Boathouse Auctions. Represented by Yacht Brokers Sean Doyle and Wes Sanford, Sapphire attracted serious interest from qualified buyers leading up to the auction, reflecting her strong market appeal.Delivered in 2009 and constructed using lightweight aluminum to ABS classification standards, Sapphire embodies the finest traditions of American yacht construction. The vessel underwent a comprehensive refit in 2019, followed by substantial technical upgrades in 2020 and 2021, including engine rebuilds and generator replacements. Recently completing her five-year survey, Sapphire entered the market in prime condition, ready for immediate use.A standout feature of Sapphire is her versatile layout, which accommodates up to 20 guests across seven well-appointed staterooms. This configuration makes her ideal for large families or as a capable mothership support vessel. Guests can choose from two triple cabins with queen and twin beds, two twin cabins with Pullman berths, and additional cabins on the main and bridge decks. The bridge-deck master suite stands out with its luxurious ensuite bath, soothing bathtub, and direct access to a private exterior deck.Zero-speed stabilizers and a shallow draft ensure smooth cruising and easy navigation to popular destinations like Florida and The Bahamas. With a 4,000-nautical-mile range, Sapphire is equally adept at long-distance travel.Outdoor spaces are carefully designed for leisure and entertainment. The sundeck boasts a relaxing hot tub, a well-stocked bar, and multiple lounging and dining options. Other al fresco areas include the Portuguese bridge, bridge deck aft lounge, and a spacious main deck aft dining table. Thoughtful integration of tender and toy storage keeps the decks clear and functional.James McFarlane’s interior design combines timeless elegance with practicality. The main salon offers ample seating, a welcoming bar, and a formal dining area for 14 guests, enhanced by an abundance of natural light. Forward of the salon lies a multipurpose bonus room that can serve as a playroom or an extra VIP suite.Featuring a proven platform, recent technical improvements, and generous accommodations, Sapphire presents an attractive option for experienced yacht owners seeking a capable, family-focused superyacht.Credits: Northrop & Johnson
April 3, 2025