By Thomas P.

Gene Extreme 499, which was introduced in 2018, is an interesting proposal in its class since it can be used either as a recreational boat or as a "pure fishing" one focusing on large deck areas.

Gene Extreme 499

With a total width of 2.45 meters and a weight of 480 kg, the Extreme 499 Rib is built on a deep V-hull with 58 degrees of bow entry and 27 degrees of deadrise at its transom.
Its hull is characterized by the presence of two spray rails per side which have a slightly negative inclination and end up to the transom with a width of 11 cm. On the Rib’s transom, a 40cm fiberglass bracket is fitted, which constitutes an extension of the hull, actively participating in the ride.

On deck

The deck of Extreme 499 manages to be particularly spacious, mainly thanks to the polyester bow, which although alters the character of the rigid inflatable boat, provides a very wide sundeck with a length of 1.40 m and a maximum width of 1.45 m.

Gene Extreme 499

The tubes stop at the height of the bow superstructure, from where the high gunwales start to run for 1.50 meters up to the anchor roller, ensuring significant lateral storage spaces that can comfortably accommodate all the lightweight survival equipment of the boat.

By applying the appropriate addition, the sundeck of the bow can be formed in a very wide bed of 1.84 meters length, while under the central pillow is housed the largest storage space of the boat.
The hard nose offers a large surface for comfortable entry to the boat, while inside it is formed a very large space for the reception of the anchor and many meters of its rope.
The console is designed in purpose to allow the comfortable movement of the occupants around, without lacking any internal storage space while it offers the proper one for all the necessary navigation instruments. It is slightly on the starboard located, leaving a very wide passage on its left reaching 53 cm, still without limiting the passageway to its right which is 31 cm wide.

Gene Extreme 499

Gene Extreme 499

The double helmseat rests on a stainless steel construction, leaving more free space on the deck, at the back of which the Bimini's stainless steel support ends which, from whatever side you see, steals the show.
Bimini's forward and flat-shaped support struts match harmoniously with the console design and end up on the deck. Its roof is double with its top one sliding so as to provide sun protection to the aft sofa.

Between the helmseat and the aft bench, there is a large free space of movement with a maximum width of 1.45 meters, a number we can find only in much larger boats.
The stern sofa can accommodate three adults with comfort, while the wide gunwales to its right and left ensure comfortable access to the engine area and the 60 cm long swimming platform that provides the necessary space for easy retreat from the sea.

Gene Extreme 499

Gene Extreme 499

At Sea

Our test Rib had been converted by its owner into a real fishing machine with two motorguides, 4 batteries, 3 sounders and a stainless Bimini with a double sliding roof. The result, of course, was to have an overweight boat with an obvious shift in its centre of gravity much more forward, mainly due to the placement of the two batteries of the electric motors in the front locker.

Gene Extreme 499

This great distortion of the boat’s balance was quite reasonable to have a negative impact on its behaviour and handling, so we were not able to evaluate it appropriately.
As we have already noted in our various previous articles, the weight distribution on a boat is of primary importance and acts as a catalyst in its performance. This effect is more evident in small boats that are particularly vulnerable, so even minor changes of their centre of gravity have dramatic effects on both the ride quality and the number of measurements.
So even the new generation four-cylinder 115 Pro XS engine of Mercury that was hung on the transom was not strong enough to move the boat which started to perform after 4000 rpm.

With 150 litters of fuel and 3 people on board, Extreme 499 was standing on plane at 3500 rpm with 12 knots and the fuel consumption was about 1.12 litters per nautical mile.
While the 13¾"x15" 3-blade Black Max aluminium propeller was struggled to pull the overweight boat on plane, it nevertheless gave us satisfactory planning speed in 5.5 seconds and the vessel reached 30 knots in 12.5 seconds.
At 4000 rpm, where the boat was running free of excessive drag, it began to show us its capabilities while, at the same time, the improved handling was evident.
At these rpm we were comfortably riding with 19 knots burning 0.92 litters per nautical mile. This was the most economical cruising speed, giving us 163 nautical miles of autonomy.

Gene Extreme 499

At 4500 rpm we were running with 22.5 knots, consuming 0.93 litters per mile, while at 5000 rpm our speed reached 27 knots burning 0.98 litters per each mile.

You can see our detailed measurements in the table below:

Perfomance data by e-Ribbing pdf

As we mentioned above, the overweight and mostly the improper weighed boat of our test affected in a harsh way its otherwise seaworthy hull. Definitely, some modifications are required in this setup, the most important of which the use of a 3-blade propeller with larger diameter and shorter pitch or a 4-blade propeller of the same diameter and pitch. So, we will benefit from the extra lift that will be offered by the overall increase of the new propeller blade area, which will help the engine to get the boat onto plane easier and hold it there at lower rpm.

Gene Extreme 499

An ideal combination for this particular boat would be the application of the 4.9-inch Command Thrust gear case of 2.38:1 ratio, which is compatible with the new 115 Pro XS, allowing it thus to spin even bigger propellers leading to a clear improvement in low rpm performance.

...keep Ribbing!




Technohull Omega 45
  • Length overall:: 4,99 m
  • Beam:: 2,45 m
  • Weight:: 480 Kg
  • Tube's diameter::0,47 m
  • Fuel tank:: 140 lt - 200 extra
  • Bow entry:: 58ο
  • Transom deadrise:: 27
  • Max HP: 140

Manufacturer: Extreme RIB
14, Lavriou Ave. Glyka Nera 15354 - Αthens
Tel.: 210 66 13 777
www.gene-rib.gr

Thessaloniki's Dealer: Delipoulios Marine
21, Thessalonikis - Peraias - Thermi 57500
Tel.: 23920 92298>