ZEN 39S – Twin 425hp XTO Yamahas
RIBCO Venom 34 – Twin Merc’s 4.6L 300hp Verados
RIBCO Seafarer 36X - Twin Mercury 5.7L V10 400hp Verados
I wouldn't be honest if I told you that the invitation to this sea trial didn't excite my driving passions, as both Mercury's new 5.7L V10 400hp Verado and Ribco's Seafarer 36X offer unique features that raise the bar very high, gaining a clear lead over the competition.
Of course, we know the Ribco Seafarer 36X very well and declare that we are fascinated both by the elegance and excellent finish of its deck and by the design features of its hull, which is one of the boat's strongest assets, contributing catalytically to its excellent performance and ride quality, composing a charismatic set that cannot but enchant even the most demanding owner.
Spacious and luxurious, it reflects its premium aura wherever you stand on the deck giving the highest possible level of living at sea, while the ergonomics and functionality offered by the general design as well as the individual accessories which are manufactured in house are an example to follow.
With two tent-type cabins, two large beds, a very comfortable and independent toilet and bathroom area, a wet bar, a four-seater sofa, two rows of seats for five people and two large sundecks fore and aft, it offers everything we need to enjoy the sea not only for our daily escapes but also for our multi-day vacations.
One of the strongest points of the boat is, as we have emphasized many times, the T-Top of the Seafarer 36X which is made entirely of carbon and fits perfectly with the console of the boat creating a single set of absolute protection against wind and spray, enabling us to come into contact with our great ‘mistress’ even on cold winter days.
All of the above become even more important because they are running on an extremely seaworthy hull, which can travel comfortably and, above all, safely, even in harsh weather conditions. Maintaining high cruising speeds and low consumption combined with soft damping and a high degree of flexibility and directional stability allow us to approach quickly even the most distant destinations.
This time, the Seafarer 36X was hosting on its transom two brand new V10 400hp Verado engines of Mercury, which we were lucky enough to be the first to test at European level.
Their technical characteristics do not leave much room for discussion or questions, as Mercury has changed its page and philosophy for good, now looking down on most of its competitors and setting the bar very high. Weighing in at just 315.2kg, 116kg lighter than its nearest competitor and 14.5kg lighter than Suzuki's 350hp V6 engine, it already carries a huge advantage. First of all it does not alter the weight distribution of already existing large boats which is of major importance in the ride quality and quite simply means that it can be hung on their transoms without any qualms. It only takes just to consider that 116 kg less weight means 232 kg less on the transom in two-engine installations and 348 kg less in three-engine installations.
In addition, Mercury has applied a 2.08:1 gear ratio to its V10 engines which together with the new and larger diameter Revolution X propellers constitute an explosive combination of torque and thrust that results in instant planning and keeping the boat on plane at lower rpm, faster cruising speeds and greater fuel economy, while ensuring that its enormous horsepower is not wasted in the water.
At Sea
Although we knew nothing about the "marriage" of the powerful new engines and their massive gearboxes with the Ribco Seafarer 36X, since it was the first time that these engines would hang on her transom, we were extremely optimistic.
The appointment was arranged in the blink of an eye and we almost ran το launch the Rib into the water, as it had to be urgently loaded to be presented at an exhibition abroad. The lower units of the engines were wearing the new Revolution X propellers, 25-inches of pitch that were the only ones available at the time.
Wednesday 01/25/2023.
Anavyssos Bay: 10am-11am.
Winds N, NΕ: 25-30knots.
Sky: cloudy.
With barely one hour at our disposal, almost speechless, we were trying to get a first feeling, listen to the new and unprecedented set-up and draw the first conclusions.
We were a crew of 3 people, with 300 liters of fuel and all the necessary equipment on board. For quite some time we were pushing forward and backward the throttles to feel the limits of the powerful engines and adjust our own handling accordingly.
Realizing that we were in complete control of the Rib, as the Seafarer’s 36X hull seemed to handle the 800 ponies of the mighty engines perfectly and literally indifferent to the huge reserves of torque hidden in their lower units, the throttles were nailed forward and we were flying from wave to wave, constantly changing course in order to evaluate both the capabilities of the new engines and the quality of riding in each wave direction.
Throttle response was magnificent throughout the whole rpm range, and a gentle touch on the throttles was enough to feel the explosive torque keeping us stuck in the seatbacks, enjoying our short and low flights as the Rib was offering very soft depreciation. The Seafarer 36X literally swept the waves and bridged their crests, leveling the sea and raising our adrenaline to levels of raw euphoria.
The combination of the numerically large reduction ratio of Mercury's new V10 engines with the new 18 inch of diameter Revolution X propellers, whose design features are more aggressive, gave us explosive grips and a feeling of high confidence and security. We had also the strong impression that we were traveling standing very high above the surface of the sea without, however, under any circumstances the Revolution X props losing their contact with the water, which is largely due to the clearly taller cup that continues its course long after the blade tips, combined with their distinctly longer barrel.
We turned our bow and put the waves on our stern. It became obvious that it was impossible to 'sink down' it into the waves’ backsides. Even at low cruising speeds, the bow proudly was passing over the crests of the waves which were by no means negligible even for boats of this size. In no mood to exaggerate, the Seafarer 36X was travelling perfectly on its own, without even requiring special manipulations from the skipper, leaving us carefree to enjoy the sea with all our senses. The Rib was jumping on plane very quickly, reaching 30 knots in 6.5 seconds and 40 knots in 8.5 seconds. It was capable of standing on plane at 2100 rpm and travelling at 12 knots, enabling us to maintain very low speeds in rough seas which meant a smoother ride and greater range.
At 3000 rpm we were cruising at 20.6 knots burning 2.8 liters per nautical mile, while at 3500 rpm we were running with 26.5 knots consuming 2.7 liters per mile.
At 4000 rpm our speed reached 33.2 knots, at 4500 rpm 40.6 knots and at 5000 rpm 45 knots burning respectively 2.65, 2.66 and 2.84 liters per nautical mile.
We therefore find out that in a range of cruising speeds from 33 to 40 knots we achieve the greatest fuel economy and therefore the maximum range, but without observing a particular increase in fuel consumption when we travel from 20 to 30 knots or faster up to 45 knots with whatever that implies.
At full throttle, the Seafarer 36X reached 60.6 knots with the engines maxed out, demanding noticeably more fuel, burning 4.4 liters per nautical mile.
You can see our detailed measurements in the table below:
During our sea trial, we lifted the port engine out of the water and tested the ability of the starboard engine to propel the boat on its own. We found out that we could travel comfortably at 4800 rpm with 26 knots burning 4.5 liters per nautical mile, while at 5500 rpm we were riding at 39 knots consuming 3.8 liters per mile.
Without any doubt, the overall performance we recorded indicates a very good set up even though it was just the first test of the new engines on this particular boat. Taking a closer look at our measurements, and particularly the low-rpm slip numbers coupled with the fact that the engines sounded to work more smoothly from 4000 rpm onwards, it makes sense that it's worth trying longer-pitch propellers at the same mounting height as well as the 25's we were already wearing by lowering the engines by one hole.
Also considering that for our own use, smaller diameter propellers can comfortably propel even larger inflatable boats, it would be nice if Mercury decided at some point to produce lower units with smaller gear ratio, and therefore less bulky, to suit its new V10 400hp engines. In this case we would be able to match much longer propellers and see even better performance in terms of cruise speed and economy, as well as higher top speeds.
Currently awaiting the longer Revolution X propellers, we'll be back with a second sea trial, when the setup from Ribco Marine is complete, and by all accounts with even better numbers...
Manufacturer:
RIBCO Marine 178
Agias Marinas - Koropiou Ave. 19400 Koropi
Tel.: +30 22910 90800
Fax: +30 22910 92159
email: sales@ribcomarine.com
www.ribcomarine.com
