Clubman 35 is the largest model of the homonymous Joker Boat's highly successful series, which impresses for its beautiful design as well as its spacious areas ideal for nautical camping.
Its deck is designed to accommodate many people in the aft U-shaped dining area, to sleep comfortably a couple in the cabin, while the raised sundeck of the bow guarantees endless hours of relaxation and sunbathing.
You can see the Clubman’s 35 deck detailed presentation at the link below
JOKER BOAT Clubman 35 – 2 x 350hp Verados.
The black color of the tubes, the teak lining of the deck, the passageways and the swimming platform as well as the dark gray gel coat of the fiberglass surfaces that matches in harmony with the color of the engines constitute a very strong combination which certainly did not leave us indifferent.
Having in mind the performance of Clubman 35 with the twin 350hp Verado engines, we were curious to see its behavior and the numbers it would give us with the powerful Yamahas mounted on its transom.
Of course, the comparison between the performances of the engines, which many of you will try to do, is not objective since the sea trials took place with different loads, in different regions and seasons, while the Ribs’ set-up was completely different.
Yamaha’s XTO 425hp engines were mounted on the transom of Clubman 35 turning 16 1 / 8΄΄ x 23΄΄ 3-blade stainless steel propellers through their 1.79: 1 gear ratio. With a crew of five people on board and 220 liters of fuel, the Rib was jumping onto plane in 4.2 seconds while accelerating from stand still up to 30 knots in 7.8 seconds.
Clubman 35 was standing on plane at 2300 rpm maintaining a speed of 13 knots, while at 3000 rpm we travelled with 24 knots burning 2.9 liters per nautical mile. This was also the most economical cruising speed giving us a maximum range of 76 nautical miles when we have 220 liters of fuel in our tank.
At 3500 rpm we were running with 27 knots consuming 3.1 liters per nautical mile, while at 4000 rpm we reached 32 knots burning 3.4 liters per mile.
Pushing further down the throttles we felt clearly that the hull was running high above the water, with a significant reduction of its wet surfaces due to the excellent stern lift of XTO propellers, while it accelerated quickly reaching immediately 4500 rpm where our speed was 37 knots and the fuel consumption 3.6 liters per mile.
Clubman 35 showed very good handling, excellent throttle response across the whole rpm range, remarkable stability during the ride and of course it was quite robust due to its very good build quality.
You can see our detailed measurements in the table below:
At WOT, the engines reached the maximum rpm recommended by their manufacturer and our top speed reached 55.5 knots.
Looking at our measurement table we will find out that the slip values for this particular boat-engines-propellers combination are quite high, indicating high degree of hull’s drag that somehow needs to be reduced.
One way to limit the slippage is to switch to 16 3 / 8΄΄ x 22΄΄ propellers, so as the engines to be able to maintain almost the same rpm. Unfortunately, however, because Yamaha does not have the above props numbers available, we will have to go to 16 3 / 8΄΄ x 21΄΄ propellers resulting in engines being over-propped when carrying on board the specific loads of our test.
It is clear that Yamaha’s propellers sizes do not allow us to run the engines as close as possible to their max operating range at WOT in each condition, nor, of course to choose the right propeller in relation with the type of our hull, our loads or use. So, we may not absolutely agree with the Yamaha’s choice to produce the XTO propellers with increased diameter while at the same time reducing their pitch since the role of prop’s diameter is quite different than the one of the prop’s pitch.
It is quite certain that many boat-engine set-ups will not be able to find the most suitable propeller to maximize their overall performance and fuel economy too.
JOKER BOAT SRL
Via S. Maria 98 – 20093 Cologno Monzese (Ml)
Tel. +39 02 2540681