It is already a reality in America, but here in Europe, we have yet to see a rib with four 425-hp outboard engines. Capelli has taken care of that with the Tempest 50, offering a boat where power and performance win out over everything. The Tempest 50 – 15 meters in length, 4.20 in beam, and a weight of 9,000 kilograms – is aimed at those who want to have a high-performance support vessel that is comfortable and easy to operate even without a crew and… definitely flashy. The four Yamaha XTOs, in fact, make this rib one of a kind: lots and lots of power in plain sight.
Capelli Tempest 50
Electric wheelhouse, world’s first 4-stroke direct injection engine with significant benefit on torque and fuel consumption, very powerful alternator (42A at 1500 rpm), alternator cooling air outlet on the forward-direction grille (unusual position for an air outlet duct, but when the engine is up, during non-use, rainwater is prevented from entering), two standard water pumps (one metal to make volume, one made of neoprene to make pressure), possibility of changing the foot oil without having to wing the boat (in fact, by removing the grille, two “little tubes” are provided through which, by creating a vacuum with the help of a pump, the foot is emptied of the old oil to replace it, using the other little tube, with the new one). To those who were considering an upgrade from the “old” 350hp to the new 425hp XTO we can say that it is entirely feasible as the wheelbase and drilling jig are the same. The only possible problem is the approval of the boat.
Capelli Tempest 50 – Design
Let’s move on to the boat. The layout of the Tempest 50, designed by Roberto Curtò, is intended to give the customer the privacy that an owner of boats of this size appreciates, even in a day-cruiser. In fact, the prototype we tested is proposed with two separate cabins, one in the bow and one amidships, to have maximum discretion on board even when accompanied by the crew.
If the solution might be uncomfortable for you, however, fear not because the possibility of revising the distribution of living spaces on board according to the owner’s needs is provided by the shipyard. The bridge is positioned decidedly forward of a normal boat of equal power and performance, but this does not unbalance the boat’s center of gravity in any way. It also makes possible the presence of a livable cockpit and a really large aft sundeck. A second lie-down is present prow of the cockpit.
The two interior cabins have a single bathroom, a kitchenette and both see provision to be fitted out as double cabins. In general, the finishing touches, especially the interior, of the boat are still a bit to be “refined”: but beware, the boat was set up in a hurry in order to be present at the Cannes and Genoa boat shows, and surely the shipyard’s attention to finishing in detail the different boats customized ad hoc for their owners will be maximum. The deck looks basic, almost bare, but on the structural parts and safety accessories such as bollards, stanchions and handrails, definitely solid and well designed.
Hull
The hull, and particularly the transom, were the cornerstone of the project, given the exceptional propulsion of the four engines. Capelli’s design of the boat and Yamaha’s design of the XTO started almost simultaneously, making it possible for the former to size the hull structure as early as possible according to the power the engines can offer.
Beams were attached triangularly to allow each individual engine to transmit power to the rest of the hull, avoiding excessive twisting due to stress on the transom in toto. The lamination of the hull was done with special resins that are very strong and anti-osmotic. The buoyancy reserves are well thought out, critical to the stability of this boat especially when turning, where the tubular, resting in the water, prevents excessive rolling even at high speeds, giving a great sense of security to those at the helm.
Underway
Let’s move on to sailing performance: the Tempest 50 is a decidedly adrenaline-pumping boat (it is the only European boat to mount four engines), fast (the power-to-weight ratio is 5.2/1), agile even at high speeds (it tightens the tack very well even at 30 knots). The hull is very smooth while sailing at maximum revolutions, a symptom of careful attention to the center of gravity and weight distribution during design.
https://www.facebook.com/barcheamotore/videos/273092646644096/
Due to the center of gravity almost at water level during the turn, at maximum roll, the outboard engine mantains the same RPM as the others, obviating the problem of the four-engine arrangement and the possible cavitation of the outboard propeller at the turn, resulting in excellent hull stability, certainly helped by the width of the boat and the buoyancy reserve of the tubular.
Capelli Tempest 50 – Yamaha outboard motors
One feature we really liked is the “virtual anchor,” with Helm Master’s Stay Point system (the platform designed by Yamaha for easy joystick maneuvering). Software, linked to GPS, locks the steering wheel and takes over the boat. In autonomy, it keeps the boat motionless at the established point, both as the coordinates of the entered staypoint and as the “degrees of heading” of the boat. There are also variations for fishing: the motors keep the degrees of heading unchanged but allow the boat to drift, or they keep the boat fixed on a staypoint but allow it to rotate, fulcruming at will on the bow or stern depending on the position of the lines in the water. All this is done by minimizing the number of revolutions so as not to agitate the waters too much during the fishing trip.
Capelli Tempest 50 Sea Trial
The shipyard seems to have paid much attention to the structural design of the hull on the basis of motorization, deriving decidedly satisfactory results. The boat is stable while cruising and on peak speeds, nimble when turning, which even at high speed suffers neither hull drift nor engine cavitation. What we liked less (the interior trim and some somewhat pronounced “edges” below deck) can be attributed to the haste of setting up the prototype for the boat shows, and we are sure it will disappear as early as the second example! HERE Capelli’s website, HERE Yamaha’s website.
Bacci Del Buono
THE TEST DATA
Headed boat with on board:
n. people |
Fuel Tank |
Tank Water |
5 |
2000 lt |
0 lt |
Engine performance:
RPM |
Speed (knots) |
Consumption l/h |
600 |
3,5 |
15,6 |
1000 |
6 |
29,7 |
1500 |
9 |
41,5 |
2000 |
10,5 |
63,6 |
2500 |
17 |
91,7 |
3000 |
21,5 |
121,5 |
3500 |
28 |
171,2 |
4000 |
33 |
227,2 |
4500 |
37,5 |
307,7 |
5000 |
41,5 |
376,2 |
5500 |
46 |
515,7 |
6000 |
52,5 |
577,9 |
Data Cruising speed:
RPM |
Speed (knots) |
Consumption l/h |
3800 |
31 |
198,5 |
Minimum glide speed:
RPM |
Speed (knots) |
Consumption l/h |
2300 |
15 |
72,5 |
Timing:
Stop-cruise speed (0-30 knots) |
Stop-speed max (0-52 knots) |
Stopping time (52-0 knots) |
Glide input time (3100 rpm/10 knots) |
7.82 sec |
29.17 sec |
15.02 sec |
4 sec |
Measurements:
Min/max passages measurement |
26 cm / 32 cm |
Cockpit walkways – dashboard |
42 cm |
Stern cockpit (walking surface) |
Length 121 cm / Width 173 cm |
Stern / bow cabin max height |
210 cm / 197 cm |