Mazziena 26SP – V8 350hp Honda
Seafighter SFR 42 – Triple V10 Mercury 400R
Mazziena 26SP – V8 350hp Honda
Seafighter SFR 42 – Triple V10 Mercury 400R
ROCK 40 - Triple Honda BF350 V8
In an era where naval architectural innovation constantly pushes its limits, ROCK 40 does not simply join the category of large inflatable boats; it comes to leave its own distinctive mark, running on a hull bearing the “heavy” signature of Ocke Mannerfelt.
Ocke Mannerfelt, one of the most influential and widely recognized high-performance boat designers worldwide, with a career spanning more than five decades, is a pioneer in optimizing stepped hulls for high speed and stability. His designs emphasize the combination of performance, safety, and control at high speeds, and have achieved dozens of world records and titles in offshore championships with boats of his own design.
The ventilated triple-stepped hull structure applied to ROCK 40 is not simply an impressive technical feature but a targeted hydrodynamic solution that drastically reduces the wetted surface area, allowing the Rib to “lighten” as speed increases. The controlled introduction of air beneath the hull reduces friction, improves fuel efficiency, and enhances linear acceleration while maintaining high levels of stability.
The 22-degree deadrise at the transom confirms the offshore orientation of the design. The deep-V geometry allows the hull to cut through waves rather than “hit” them, effectively absorbing impacts and offering exceptionally smooth navigation even in difficult sea conditions. The result is a boat capable of maintaining high average cruising speeds with safety and control, without tiring either crew or helmsman.
In practice, this hull geometry translates into solid grip in turns, predictable behavior at the limit, and a feeling of complete connection with the helm. ROCK 40 is a boat that does not simply pursue top speed, but focuses on the overall quality of navigation and usability—something immediately perceived by the operator.
On Deck
Rock 40 has been designed to offer a complete day-boating experience, while also providing full autonomy for multi-day escapes.
With carefully studied ergonomics and generous deck spaces capable of accommodating more than 10 passengers, it creates ideal conditions both for relaxation and for social moments underway. Whether cruising or anchored in a quiet bay, the generous surfaces and well-designed seating layout ensure that every outing at sea becomes a comfortable and enjoyable experience for everyone on board.
The large-diameter tubes surrounding the bow deck enhance the feeling of safety, while the wide walkways on both sides of the beautifully designed cabin ensure comfortable movement for passengers. The overall layout radiates a balance between functionality, elegance, and ergonomics-key elements of Rock 40’s design philosophy.
The large delta-shaped sunbed located on the cabin roof creates an ideal space for sunbathing and relaxation, comfortably accommodating two adults. Slightly forward we find an elegant double seat, a small “balcony” over the sea. From there you can let your gaze drift toward the horizon and feel the magic of navigation, far from any noise.
It is that liberating rhythmic sound of the hull gliding over the water, as the bow gently rocks and slices through the sea with a sense of freedom that is difficult to put into words.
At the center of the deck stands out the cleverly designed side door leading to the protected cabin area. Entering through the comfortable entrance, three steps take us inside, revealing a beautiful living space that provides all the essential comforts even for multi-day trips.
To the right is the door leading to the independent bathroom, a fully functional and carefully designed space that offers comfort even for tall adults. Its layout has been designed with practicality in mind, housing a toilet, sink, and small useful storage spaces for personal items. There is also a separate shower area, allowing for a quick and refreshing wash after a swim.
On the left side is the large double bed of the cabin, a comfortable resting area that can accommodate two adults without compromise. The cabin offers adequate headroom, creating a pleasant sense of spaciousness and allowing for a truly comfortable living environment.
Three elegant portholes provide natural lighting and proper ventilation for the cabin, allowing daylight and the sea breeze to gently enter the interior. As a result, the space acquires a warm and welcoming atmosphere, ideal for moments of relaxation after a full day at sea.
The Helm Station
The cockpit of Rock 40 has been designed with a clear focus on ergonomics and vessel control. The dashboard is spacious and properly configured, allowing the installation of large navigation displays and engine information screens. The slight angle of the console has been carefully designed so that the readings remain easily visible from any driving position, whether the helmsman chooses to operate the boat seated or standing.
At the center of the console sits the steering wheel, symmetrically framed by navigation screens and engine instruments, ensuring immediate and effortless visual access to all essential navigation information. This layout allows the helmsman to maintain full control of the boat at all times without being distracted from the surrounding sea environment.
Particularly impressive is the excellent forward visibility and view of the horizon while driving in a seated position. This becomes a significant advantage during a journey, especially when sea conditions become more demanding, providing the helmsman with confidence and better awareness of the navigation field.
The T-top integrates harmoniously into the overall design line of Rock 40, following the dynamic lines of the boat without disturbing its aesthetic balance. Combined with the windshield that connects the structure to the cockpit, it creates a protected area for both helmsman and crew.
This arrangement provides effective protection from both intense sunlight and wind during navigation, allowing comfortable use of the boat in any season. Thus, Rock 40 remains equally enjoyable not only for summer outings but also for cooler winter escapes at sea.
A fully equipped wet bar ideally complements the deck’s functionality, featuring two refrigerators, an espresso machine, and a sink. This thoughtful configuration ensures that all essential comforts are always within easy reach, allowing the easy preparation of a refreshing drink or coffee without interrupting the enjoyment of being on board.
The Stern Area
At the stern of Rock 40 we find a particularly spacious seating area designed to serve as the main gathering and relaxation point for crew and guests. Its layout allows many people to be accommodated comfortably, while thanks to its flexible design it can transform within seconds into a large and welcoming dining area for meals or social moments underway.
The area consists of a three-seat sofa facing aft and two large L-shaped sofas that frame two height-adjustable tables, offering flexibility depending on the needs of the moment. A particularly practical feature is the provision for a comfortable passage between the sofas, allowing easy and natural access to the engine area without needing to step over the seats.
Another clever design element is the reclining backrests of the aft sofas. When tilted toward the stern, they significantly expand the relaxation and sunbathing surface, transforming the rear section of the boat into a large and comfortable area where passengers can enjoy the sun and the sea in total comfort.
At Sea
Honda’s new outboards, with their imposing and aerodynamically sculpted cowling, matched perfectly with the dynamic character of ROCK 40, visually and practically reinforcing the boat’s performance profile.
Beneath the single-piece cover lies an all-new 5.0-liter V8 engine, featuring a fully balanced, high-strength crankshaft. Its alloy composition and manufacturing specifications reflect the expertise used in Acura high-performance engines, translating into exceptional durability and mechanical precision.
The 60-degree V8 configuration allows ideal operating geometry, minimizing mechanical vibrations and noise, contributing to a smoother, “velvety” operation throughout the entire RPM range.
In terms of performance, the BLAST (Boosted Low Speed Torque) system plays a decisive role at low RPM, optimizing ignition timing to provide immediate throttle response and increased torque during acceleration. The result is dynamic starts, faster planning, and a smooth transition toward mid and high RPM. At the same time, Lean Burn Control technology precisely adjusts the fuel-air mixture, achieving significant fuel savings-up to 17% at cruising speeds-without compromising performance.
During the test, what stood out was the refined operation of the engines: linear power delivery, complete absence of unpleasant vibrations, and extremely low noise levels. Particularly in the mid-range RPM band -where a boat usually travels during cruising- the silence in the cockpit allows comfortable conversation without raising your voice. An experience that does not merely reflect the 1,050 horsepower of the triple installation, but refined mechanical superiority clearly oriented toward comfort and control.
Performance Test
It was the first time the transom of ROCK 40 carried Honda’s new 5L V8 350 hp engines, whose gearcases turned 16” x 21” ECO Enertia propellers with a 1.79:1 gear ratio. With 450 liters of fuel, four crew members, and all the boat’s equipment onboard, we headed out to sea for a short run to get our first taste of this newly introduced setup.
For quite some time I “played” with the throttles to gain a first impression of both the engines’ power and the boat’s response, which seemed to manage the enormous torque reserves of the powerful V8 engines with ease. ROCK 40 maintained on plane at 2400 rpm and 14 knots, accelerated to 30 knots in 7 seconds, and reached 40 knots in 10 seconds.
Throttle response and explosiveness were at a very good level, as was the boat’s stability - even when performing sudden maneuvers at high speeds. Both our impressions and the recorded figures indicated an excellent setup and a very good combination of propellers and engines mounting height.
At 3000 rpm we cruised at 26 knots, consuming 2.9 liters per nautical mile.
At 3500 rpm, speed increased to 32 knots with consumption at 3.2 L/nm.
At 4000 rpm, speed climbed to 37 knots, with consumption at 3.7 L/nm.
At 4500 rpm, cruising speed reached 42 knots, and at 5000 rpm, 47 knots, consuming 4.1 and 4.5 L/nm respectively, with propeller slip dropping below 3%.
At wide open throttle, the engines reached 6200 rpm and ROCK 40 achieved a top speed of 57.5 knots, recording 3.9% slip - figures that demonstrate an excellent setup.
📊 Our detailed performance measurements can be seen in the table below:
Analyzing our measurement data, we observed particularly low propellers slip values with these propellers and engines mounting height. This confirms that the entire setup has matched perfectly, with a very well-studied configuration that fully exploits both the engine power and the hull design without requiring any additional intervention or improvement. Although during our tests the engines slightly exceeded the maximum recommended limit by about 200 rpm, this should not be considered negative. On the contrary, it indicates that the propellers choice and overall setup were selected with the correct logic.
In practice, this means that when the boat travels fully loaded - with full fuel tanks, additional equipment, and more crew - the engines will still operate very close to their ideal maximum RPM range, delivering full power without being “choked”. This ensures that the boat will maintain its performance and efficiency even under the most demanding load and sea conditions.
With Two Engines…
We raised the center engine and continued navigation with only the two outer engines operating. Despite the boat’s significant weight and dimensions, Rock 40 planed without much effort, proving the efficiency of the hull geometry and propulsion combination. Within just a few seconds we were traveling at 34 knots at 4000 rpm, with the engines running smoothly and showing no signs of strain.
These performances translate into a very comfortable and fast cruising speed, ideal for quickly covering the distance to a nearby port or destination.
At the same time, this test highlighted one of the key advantages of a triple-engine installation: even with one engine out of operation, the boat maintains high performance and full functionality, offering an additional level of safety and flexibility in navigation.
Manufacturer:
ROCKMARINE
Thorikou Avenue - 19010 Kalivia
Tel.: +30 2113331200
Email: contact@rockmarine.com
www.rockmarine.com
