By Thomas P.

A few years ago it was unthinkable even to imagine that a pleasure Rib could be powered by so much outboard engines horsepower of a total 1700hp. Not only were there any powerful outboard engines but also not so strong transoms to accommodate them too. Nowadays, everything seems to be possible and the answer comes from Capelli and Yamaha!

Capelli Tempest 50'

The Capelli Tempest 50 Rib made its first official appearance in Italian waters at the 58th Genoa Boat Show and, as expected, all eyes were attracted on it.

Tempest 50 is not just another wonderful mega-rib. It is a rigid inflatable boat with highly-acclaimed design that opens up new roads and leads to another level, which can be superior to even the big luxury cruisers at the points.

Its mission is to accomplish long-distance cruises at high speed with the comfort and luxury that characterizes a large cruiser, accommodate the family and guests of the owner in separate and independent cabins, as well as to provide enormous space on the deck where lots of people can move free, entertain and have fun.

Tempest 50 now consists the flagship of the Capelli boatyard, its total length is 14.80 meters, its total width 4.30 meters and weighs 9.000 kg excluding the engines.

Capelli Tempest 50'

Undoubtedly, it is a boat for a limited target group of buyers which we had the pleasure of testing and enjoying the luxury and comfort it offers, providing us with high levels of cruising and a unique experience.

On deck

The design of the Tempest 50 deck follows the same successful formula of the smaller shipyard models, with a major difference of the independent guest cabin, first seen on a rib, located between the helm seats and the aft lounge.

Capelli Tempest 50'

The guests' cabin is accessed from the two sliding glassy doors facing each other, to the port and starboard of the cabin.
Without having to stoop at all, we went down the two steps and found ourselves inside.

What immediately impresses is its large height that exceeds two meters and the unlimited natural light that enters its interior thanks to the overhead skylight along with the large lateral windows and the glassy doors.

Besides the stairs, in the front side of the cabin, there is a galley with sink, faucet, oven and fridge, providing the appropriate space for breakfast, lunch or drink preparation. The rest is a very comfortable and spacious living room with two single beds and a table in between.

Capelli Tempest 50'

The lateral surfaces of the cabin host small lockers that ensure the necessary storage spaces for the fitting of the clothes and the small objects of the guests, providing plenty of storage solutions.

Without a doubt, the guest cabin is the strongest point of Tempest 50 and an area that seems to have a great comparative advantage over the other Ribs of similar size.
It is certain that the guests will love having their own private space, which provides them with a very high standard of comfort and living.

Capelli Tempest 50'

Moving forward, we see the three individual helm seats which are mounted on the roof of the guests’ cabin, just above the kitchen. They afford individual folding bolsters enabling the operator and his co-drivers to adjust the riding positions according to the circumstances.

Taking my position in the driver's seat, I was observing the electronic equipment and controls around the steering wheel.
The multi-level dashboard surfaces provide the space for the installation of large devices and are properly tilted so as the operator to be able to inspect everything at a glance.
Centrally positioned, just above the steering wheel, there is the large and elegant Raymarine's multifunctional display and above it the Yamaha’s 7-inch CL7 multi-function display.

Capelli Tempest 50'

The engines controls are located on the starboard, with the Trim Assist that adjusts the trim of the engines according to conditions maximizing performance and fuel economy.

Just ahead of the levers, there is the incredibly precise and easy to use Helm Master System, allowing the captain to move the boat in either direction, diagonally or even to pivot it 360 degrees in place.
To the port of the steering wheel there is the sliding door that gives access to the captain's cabin, while from both sides of the cockpit there are wide steps leading to the comfortable passageways to the foredeck.

Three steps lead inside the enormous cabin in the headroom of which up to four tall people can stand upright with comfort.

Capelli Tempest 50'

With a maximum height which by far exceeds two meters, the cabin has a separate toilet and large storage spaces, while the table located towards the bow can be lowered and by placing the proper cushions to form a huge V-berth.

The long windows along the lateral sides of the cabin, as well as the large skylight on its roof, ensure its natural light and create a very pleasant place to stay.

Capelli Tempest 50'

Capelli Tempest 50'

Behind the centrally located guest cabin the aft deck is extended which is the main gathering area featuring large and spacious sofas under which large storage spaces are housed.

With the table in between, the appropriate space is created where Tempest 50 passengers can enjoy their lunch or drink.

At least eight people can sit comfortably around the table and enjoy the sea when the boat is anchored on a beautiful bay or even when underway.

Directly behind we find the huge aft sun pad which offers comfortable relaxation space to lay down at least four people.

Capelli Tempest 50'

To its port and starboard there are particularly wide passageways to move easily fore and aft, while beneath it the largest storage space of the boat is hosted.

Despite the huge space occupied by the four outboard engines, there are comfortable swimming platforms on each side providing easy boarding.

Capelli Tempest 50'

At Sea

On our test Rib, four new 5.6L V8 425hp Yamaha XTO outboards were hanging, which is also the maximum horsepower rating for the Tempest’s 50 transom.
The Yamaha XTO outboards, one of the most technologically advanced engines, have a gear ratio of 1.79:1, run the industry-high 12.2:1 compression ratio with a WOT range of 5000 to 6000rpm and in our sea-trial were turning 16 3/8" x 21" ΧΤΟ 3-blade stainless steel propellers.

Capelli Tempest 50'

I had the unique opportunity to test the Yamaha's XTO in a quad installation on the Capelli Tempest 50 at the 58th Genoa Boat Show and I was looking forward to going out of the port, pushing the throttles forward to hear them roaring and feel their 1700 horses’ power.

Carrying 11 people and about 1000 litters of fuel, the quad Yamaha 425s engines jumped effortlessly on plane in a few seconds, and we were running with 15 knots at 2500 rpm. This is an excellent performance indeed, considering that the total test weight the engines were called to push reached the 13 tons.

While we were running with 20 knots at 3000 rpm, I pushed down the throttles and my back got stuck in the seat back as the engines rapidly accelerated the 15-meter rib reaching 40 knots.

If you were asking me to use only one word to describe what really impressed me, I would definitely say the incredible Torque of the Yamaha XTO engines.

However, this enormous torque would be lost if it was not combined with the new Yamaha’s propellers, since it could not be able to move bigger boats by itself (a combination that for example is missing from the Seven Marine resulting in the high slip numbers especially in the twin engines installations).

Capelli Tempest 50'

The new large-diameter XTO OS propellers translate the tremendous torque into incredible thrust, which is necessary to move a big boat. Indicatively it is mentioned that the new propellers offer 14% more blade area than the Saltwater Series XL propellers designed for the F350. According to Yamaha the XTO Offshore 425 produces 150 percent more thrust than the F350.

At 3500 rpm we were running with 27 knots burning 169 litters per hour. This was also the most economical cruising speed since at 4000 rpm our speed was 33 knots while consuming 237 litters per hour.
At WOT, the engines were turning 6000 rpm producing 53 knots with a fuel consumption of 525 litters per hour.

You can find the detailed measurements in the PDF below:

Perfomance data by  e-Ribbing pdf

Taking a good look at our analytical measurements, we find out that we had in our hands a very good set-up, in terms of engines mounting height and props’ dimensions, with impressively low slip numbers, considering the total load the engines were pushing. Indeed, this set-up provided amazing performance!

Of course, the owner of a such class boat may not be interested in the time to plane, the acceleration up to 30 knots or the fuel consumptions, but would definitely be interested in the combination of abundant torque at the midrange rpm and the tremendous thrust of the large propellers which will keep the boat on plane at low speeds in rough seas and will help it climb easily on the big waves’ back.

Capelli Tempest 50'

I was also surprised by the level of the ride quality during of which the 15-meter Rib showed a great flexibility that we have not met in such big sizes offshore boats yet.
This is mainly due to the high degree of the stern lift provided by the four XTO propellers, resulting in raising the running height of the Tempest’s 50 hull in the water which rides over the waves even at the midrange rpm. This has a big benefit in turn: reduces the drag by reducing the total hull surface that is in contact with the water increasing thus the cruising speed and leading to the fuel economy.

Regarding the sound levels of the new XTO engines seems to be much lower than the F350, if it does not fool me the fact that the Tempest’s 50 helm seat is far ahead.

The day of our test, the wave height did not exceed one meter, and so I was often turning the bow to our wakes trying to evaluate the behaviour of the 15m Rib’s hull.

What I can safely say is that Tempest 50 was crossing with solid feeling and great ease every wave, throwing the water away from its hull, and it is sure it can handle safely rough seas while having nothing to envy from the comforts offered by a cruiser.

Capelli Tempest 50'

On the way back to the port we asked Umberto Capelli what he had in mind when he was designing this Rib:
«Tempest 50 is designed to offer privacy to the owner's guests and focuses on the comfortable and pleasant living of many people on the deck, who can also have fun enjoying their drink and music by the sea».

...keep Ribbing!



Capelli Tempest 50'
  • Length over all: 14.80 m
  • Beam: 4.30 m
  • Weight: 9000 Kg
  • Fabric: ORCA NEOPRENE HYPALON 1670 dtex
  • No Pax: 18
  • Max power: 4 x 425hp

Cantieri Capelli S.r.l.
Via delle industrie, 19
26020 Spinadesco - Cremona (Italy)
Tel. +39 0372 491399 Fax + 39 0372 492115
This email address is being protected from spambots. You need JavaScript enabled to view it.

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