By Thomas P.

Weather forecast: Steep, breaking seas, wave height 1.5-2.5 meters. North winds with a speed of 22 - 27 knots and gusts of 30 knots.
Weather conditions that are usually prohibitive for many boats, but not for ZEN 39 which seemed to be in its natural environment.

ZEN 39

Without a second thought, I accepted the invitation of Nasos Nikas, the owner of Zenmarine.gr, for the new ZEN 39 sea trial.
The conditions seemed ideal for the length but also the strong characteristics of the hull of ZEN 39, which starts with a sharp bow entry of 62 degrees to reach the almost extreme deep V of 25.5 degrees in the transom area, without the presence of pad.
Elements by themselves which are capable of raising your adrenaline. Especially the view of the narrow and knifelike bow that indicates from the beginning its offshore orientation.

And of course, it didn’t take me long before I took my place behind the console which provided me with a wonderful view of the bow, allowing me to have its complete control over the horizon and the high peaks of the waves.

We went out, west of the Patroclus islet, with our bow marking the south and the waves coming to our stern.
ZEN 39 was challenging me to have the throttles almost permanently nailed forward, while as we moved away from the shores the height of the wave were increasing and the propellers steadily pointed at the bottom of the dark waters.

The bow was standing firmly up and penetrated waves, than plowing through them, effortlessly with absolutely no nailing tendency, while the hull was bridging the waves and its very deep V ensuring a very smooth ride with absence of spray on the deck.

ZEN 39

Knowing the disadvantages of the deep-V Ribs, I insisted on riding to the back of the waves for quite some time looking for some irregular waves. We may feel uncomfortable when traveling in head seas hitting the waves with our bow but the really dangerous situation is one in which the weather is coming just behind us.
Ribs go out of control in following seas, not in head seas.
Especially when driving a deep-V hull, where if the sharp bow entry sinks in the back of the wave it can brake and steer the boat abruptly with unpredictable consequences.

The best antidote is mainly the high angle deadrise at the transom in combination with the proper balance of the boat and these are the reasons why ZEN 39 in no way did it show us the tendency to read the waves so we were feeling very safe despite the high speed we developed.
A hull made for rough seas must be able to handle following seas.

ZEN 39 tends to overturn another "doctrine" that says: “the higher the deadrise angle the slower the boat and the greater the need for more horsepower”.
It is very impressive that a 39-feet Rib with extreme deep V and full of loads is capable to run with only 600 horses on its back.
And in fact, without having the feeling that more power is needed since the accelerations and fuel consumption were impressive as well as the throttle response and its final speed.

It is worth noting that even when we were landing from a great height, in no case did we receive poundings or other annoying noises, which further increased our confidence and showed the robust construction of the boat and the very good fit of all its moving parts.
It was really a tough test for ZEN 39!
Feeling very safe in the comfortable bucket helm seat, I was enjoying our wonderful ride completely indifferent to numbers and performance at the time.

ZEN 39

At some moment I turned my bow to the north where the deep V of the hull of ZEN 39 had a clear advantage. Not expecting anything different, the high deadrise angle combined with the length-width ratio, which is much larger than the minimum recommended of 3.5 to 1, did what they were intended to do. Extremely soft cruising which became even more impressive as I was pushing the throttle forward, with the Rib maintaining a very good riding angle.

Another special thing was also my feeling that the aft portion of the hull seemed to hold the Rib low and keep it in constant contact with the water, preventing it from taking off. This slight "suction" that I received was obviously a product of the partial vacuum created due to the counter-designed step that starts from the height of the helm seats.

ZEN 39 has all the specifications to travel fast, up to very fast, in the specific conditions, and the cruising speed depends on the experience and mainly on the perception of the driver who has the steering wheel in his hands.

Regarding our measurements, with 650 liters of fuel and 4 people on board, ZEN 39 was standing on plane at 2700 rpm with 14 knots burning 44 liters per hour.

ZEN 39

At 3000 rpm, our speed was 19 knots with the engines asking 2.47 liters per nautical mile, while at 3500 rpm we were traveling with 27 knots burning 2.4 liters per mile.

Personally, I find the above fuel consumption numbers surprising if we consider the length of the boat, its "small" horsepower, and the loads we carried and of course the weather conditions that prevailed during our sea trial. Honestly, I will seek another test in the near future because these numbers seem elusive even for the most optimistic scenario.
Note also that the 300hp Verado engines which turning the 16΄΄ x 19,5΄΄ XP ECO Enertia propellers were planning the Rib in 5 seconds while accelerating it in 9 seconds to 30 knots and in 14 seconds to 40 knots.

Of course, our surprise continued when we found out that at 4000 rpm we were running with 33 knots burning 2.42 liters per mile, while at 4500 rpm we were traveling with 38 knots consuming 2.55 liters per mile.

ZEN 39

Really, I do not remember ever seeing lower consumption in similar boat-engine combinations. It is great to have almost the same fuel consumption of 2.5 liters per nautical mile on average, in a wide range of speeds from 19 to 38 knots.
And this of course means that we can travel at high speeds even in bad weather conditions without the dramatic increase in consumption observed in other boats, resulting in greater autonomy.

At wide open throttle, yes we could push the throttles totally forward even in these weather conditions, ZEN 39 reached 52 knots and the engines reached their maximum recommended rpm.

The detailed numbers of our measurements can be seen in the following table:

Perfomance data by e-Ribbing pdf

The slip percentages that we recorded after 3500 rpm were also amazing.
It is really rare to see the slip eliminating at WOT and get the most out of your propellers, running at their absolute, theoretical speed.
ECO Enertia propellers and their excellent design features keep the boat out of the water and minimize wet surfaces, resulting in high cruising speeds and maximum fuel economy, despite the loads they carry or the bad weather conditions.

ZEN 39

Of course, we must also give “credit” to the geometry of the hull, which bears the main share of these performances in combination with the selective interventions of the manufacturer.

So, when we have such nice numbers we can only admit that the Rib was perfectly balanced, constituting an exemplary set-up in terms of performance.

On deck

No Rib is perfect for everyone, but every Rib has its ideal owner.
As we have pointed out several times, we cannot have it all to the fullest. If your priority is soft and comfortable cruising even in bad weather conditions then we have to sacrifice space and accommodations on deck.

ZEN 39

If the very deep V of the hull is not a high priority for you and does not go hand by hand with your use while at the same time you prefer plenty of space on the deck for entertaining then the ZEN 39 is simply not for you. Certainly its narrow bow places restrictions on living on board while the cabin and bathroom do not refer to luxurious suites.
However, this does not mean that the cabin of ZEN 39 cannot comfortably accommodate two adults.

ZEN 39

Its berth is 1.95 meters long, 1.27 meters wide on the headrest, while its width in the foot area reaches 1.97 meters.

To the right and left of the berth there are two very useful long and narrow shelves, ideal for placing small items, books and equipment that we want to have direct access to.

To the left of the headroom there is a very large cupboard while under the pillows of the bed there are two large lockers that can accommodate all the equipment of the cabin.

The headroom of the cabin has a height of 1.73 meters, while the independent bathroom has dimensions of 1.76m x 0.80m x 0.65m and all the necessary cabinets for easy access to the electrical installation of the console.

ZEN 39

Although the pilot station looks quite limited, it can even accommodate large navigation screens and any instrument we consider necessary. As you can see in the image below, in addition to the two large screens, the panel houses a radio-cd, Hydrotabs and the stern thruster controls, while it also has two useful cup holders on the right and left.

ZEN 39

The windshield is raised high and in combination with its small extensions on the port and starboard, it completely protects both the instruments and the co-pilot from the spray and the wind.
A step, to the right and left of the console, leads to the pasagewqay to the bow area.

In the right image you can see the ideal view to the bow that the height of the cabin ensures and allows us to control it directly when we sit in the steering position.

This is a very important fact, especially when traveling in bad weather conditions and we must accurately calculate the position of the bow in relation to the peaks of the waves at all times.

The small hard nose of the bow is lined with teak and is located between the junction of the tubes.

ZEN 39

A very small hatch gives access to its interior, which is very limited, but ideal for the bow lines.

Further back, and slightly elevated from the rest of the deck, is the anchor locker. Divided into two compartments, it has in one, the windlass motor and the electrical installation and in the other, the chain of the anchor.

ZEN 39

ZEN 39

Behind the anchor’s locker, the largest storage space of the bow is formed which has a great depth due to the sharp bow entry of the hull.
In the front part of the cabin - console there is a built-in double seat, designed in such a way that we can comfortably enjoy either sunbathing or riding when the weather conditions allow.
The passageways leading to the helm station are quite narrow and slightly lower than the height of the tubes.

ZEN 39

ZEN 39

ZEN 39 may be quite narrow in the bow area, but the stern lounge is large and has nothing to envy wider boats, offering comfortable living for nautical camping.

The stern cockpit can be configured with the two rows of seats as you can see in the picture below or with a wet bar in place of the rear seats.
With a width of 1.93m, the stern sofa can comfortably accommodate four people, while underneath there are two independent storage spaces, one for the refrigerator and one for equipment.

ZEN 39

The sundeck of the stern has a central passageway that leads to the swimming platform, while with the appropriate addition it turns into a large sunbathing and relaxing berth.
It is lifted by an electric mechanism and its interior can be configured in a second cabin that can accommodate two adults.

ZEN 39

ZEN 39

The swimming platform is quite large, offering the necessary space for our entry and exit from the boat as well as for our marine activities.
Of course, if this is possible, we would prefer the engines hoses to pass under the platform which can be extended several centimeters to the port and starboard by placing a sliding ladder in parallel so that we can move freely without the risk of injury.

ZEN 39

In the highlights of ZEN 39, keep in mind that despite its long length, it is incredibly capable of moving with dignity with just 2 x 300hp outboard engines on its transom, providing amazing fuel consumption even when loaded or traveling in rough seas where it finds its best himself.

It is also a pure rib, with the R capital, without oversized polyester constructions having the tubes being imposed in the overall layout as befits an original inflatable boat and it is certain that it will directly find the place it deserves among the mega Ribs of the market, gaining its own loyal followers.

...keep Ribbing!

 

 

ZEN 39
  • Overall length: 12.03 m
  • Beam: 3.22 m
  • Dry weight: 2500 kg
  • Fuel tank: 800 lt
  • Water tank: 150 lt
  • Max power: 2 x 450 hp
  • Homologation CE: Category Β

Manufacturer:
Zenmarine.gr
Tel: +30 6945 550 661
www.zenmarine.gr
e-mail: sales(a)zenmarine.gr