Mazziena 26CC – 2 x 200hp V6 Mercury
Seafighter SFR 42 – Triple Yamaha 350 V6
Mazziena 26CC – 2 x 200hp V6 Mercury
Seafighter SFR 42 – Triple Yamaha 350 V6
ROCK 36 - Twin V6 300hp Yamaha
The primary goal of the people behind the Rock Marine brand is to create boats capable of offering truly unforgettable experiences to those on board, whether they are cruising or anchored in a quiet bay. This philosophy is reflected in every model produced by the company, where performance, comfort, and functionality are combined with the aim of turning every outing at sea into a complete experience.
In exactly the same spirit moves the new Rock 36, a large performance RIB designed to offer high cruising speeds without making compromises in space and everyday usability. The balance between its sporty character and the comfort of the deck is a key element of its design philosophy, allowing the crew to enjoy every moment at sea.
At the bow area of Rock 36 we find a particularly large relaxation and sunbathing surface, designed to comfortably accommodate several passengers. Beneath this large sunbed lies a practical tent-type cabin space, capable of comfortably hosting two adults and providing a protected resting area during the day or even for a short stay.
Further forward stands out the fiberglass nose, positioned slightly lower than the level of the inflatable tubes, contributing both to the aesthetic balance of the bow and to functionality during mooring, provided that the shore cleat is positioned at a higher level. On its upper part there is a discreet hatch that provides easy access to the anchor compartment. The anchor sits precisely within the stainless-steel bow structure, creating a clean and elegant result that combines practicality with a refined finish.
The console is centrally positioned, leaving wide passageways on both sides to ensure comfortable fore-and-aft movement for passengers, while the bucket seats, mounted on a fiberglass structure, provide very good lateral support for both helmsman and co-helmsman.
At the stern of Rock 36, the main gathering area for passengers is formed. A large U-shaped sofa, combined with a two-seat sofa facing the engines area, creates a particularly comfortable lounge area ideal for moments of relaxation or social interaction on board. With the appropriate table configuration, this space can very easily be transformed into a spacious dining area capable of accommodating several people.
Further aft, toward the engines area, a large flat deck surface is created that serves multiple purposes. Here we find the space for the stern anchor, while at the same time ample room is provided for movement during water activities, facilitating access to the sea and generally improving the usability of the aft section of the boat.
At Sea
The new white Yamaha V6 300hp engines matched perfectly with the equally white colors of Rock 36, visually and practically enhancing the boat’s character. The Yamaha 300hp V6 engines represent one of the most reliable and complete options in the category of large high-performance outboard engines. With a displacement of 4.2 liters and modern design, they combine high power with smooth operation, offering abundant torque reserves throughout the entire rpm range.
The engines’ lower units were turning 16'' x 21'' ECO Enertia propellers with a 1.75:1 gear ratio, a combination that from the outset indicates the setup’s orientation toward efficient power transfer to the water.
With approximately 300 liters of fuel in the tanks, two crew members, and very favorable weather conditions on our side, we headed out into open sea in order to record the performance of this specific combination and see in practice how the package performs on the water. From the very first minutes of the test it became clear that the boat effectively utilizes the available power, allowing us to form a clear picture of its behavior and capabilities under real navigation conditions.
Rock 36 remained on plane at just 2100 rpm with a speed of 12 knots, while it accelerated to 30 knots in 7 seconds and reached 40 knots in 10 seconds. Throttle response and acceleration were at a very good level, as was the stability of the boat both at wide-open throttle and during the sharp maneuvers we attempted at fairly high speeds. The feeling from the driving positions was very positive, with a particularly high level of navigation quality.
At 3000 rpm we cruised at 28.5 knots, consuming 1.9 liters per nautical mile, while at 3500 rpm we ran at 34.5 knots, consuming 2.2 L/nm. At 4000 rpm, our speed reached 38.5 knots with consumption at 2.5 L/nm.
At 4500 rpm we traveled at 43.5 knots, and at 5000 rpm at 48 knots, consuming 2.8 and 3.5 L/nm respectively.
At wide-open throttle, the engines reached 5700 rpm, and the Rock 36 achieved a top speed of 55 knots, recording only 2.2% propeller slip.
You can see our detailed measurements in the table below:
Analyzing our measurement data, we observe very low slip values throughout the entire rpm range with these propellers and with the engines mounted at their current height.
However, we should not rush to characterize the test combination as an ideal setup, because the engines were not able to reach the maximum rpm limit recommended by the manufacturer.
In practice, this means that when the boat travels fully loaded -with full fuel tanks, additional equipment, and more crew members- the engines rpm will drop below 5500, resulting in engines that will not operate within their optimal range.
To achieve an ideal setup, it is therefore necessary to move to lower-pitch propellers, while maintaining the same diameter, which appears to match very well with the hull geometry of Rock 36.
Manufacturer:
ROCKMARINE
Thorikou Avenue – 19010 Kalivia
Tel.: +30 2113331200
email: contact@rockmarine.com
www.rockmarine.com
