Stabilization to reduce roll and pitch proposed by Humphree

Stabilization to reduce the roll and pitch offered by Humphree.

You are looking for maximum comfort on board for you and you guests? There are now, and have been for several years, very interesting solutions including adding stabilization to built boat.

Major manufacturers such as Azimut Yachts, Princess Yachts, Sunseeker Yachts, Sanlorenzo, Ferretti, Pershing and Riva incorporate one or more stabilization systems, admittedly they are available from the initial order.

You often hear about stabilization by a gyroscope sold by brands like SEAKEEPER or QUICK. These are quite expensive, roughly $70,000 to $100,000 USD and not always possible to install on a boat after build.

GYRO  SEAKEEPER                                                  GYRO   QUICK


This article aims to show you the alternatives that are available on the market when stabilizing your boat is on your agenda.

Below you will find a very interesting drawing depicting  pitch and roll on a boat:



So you are looking to obtain effective stability on board your boat?  Let us take a look at a much cheaper and very efficient alternative. These are the INTERCEPTORS by the Swedish firm HUMPHREE, which is owned by Volvo Penta. They are available for installation on boats over 25 ft.

In fact, the Humphree interceptors are a great improvement to the conventional trim tab which is found on a large proportion of boats.

The Humphree system incorporates a 5 to 7.5 cm stainless steel blade, which acts on the longitudinal plate of the boat in the manner of a flap (trim-tab) and in addition doubles as an antiroll function.

It is a sophisticated alternative to traditional hydraulic flaps (trim-tab).

Conventional Trim Tab


This system (Humphrey-made Interceptor) works with a gyroscope, accelerometer and servomotor that will slide the Interceptor’s blade in fractions of a second, talking about 0.7 seconds for a full deployment to correct the inclination of the boat on the spot. At first glance, the capacity of this blade of 50 to 75 mm, depending on the model, will correct the pitching in real time.


Its installation requires drilling the transom.

First of all, don’t expect to get any results at low or high speeds. Humphree’s active stabilization works optimally over a range of use that we estimate to be between 12 and 22 knots. It takes some water pressure (which passes under the boat) to make it work.

Therefore, if the speed of the boat is below 10 KN, the water pressure on the blades will be insufflaient for the HUMPHREE to operate in a noticeable way.


This system will allow you to reduce fuel consumption only slightly (from 3/4 to 1%), but will probably allow you to reach plain faster and acquire an additional 1kn to the top speed.

Depending on the boat (and its hull), the HUMPHREE system will allow you to reduce the roll from 45% to 55%, which is very appreciable, of course at an approximate speed of 20 kn.

It is possible that the reduction in fuel consumption is more substantial as well as the speed gain, it depends greatly on the type of hull and type of boat.

One thing is certain, nauseous boaters will greatly appreciate this system, it will make a big difference on board and you will probably be very happy to have it installed.

In a nutshell, the benefits of this system, as stated by the manufacturer:

Increases stability by nearly 50% to 55%

Reducing fuel consumption

Automatic trim control, roll and cornering

Replaces traditional trim systems (trim tab)

Easy to install, unmatched performance

HUMPHEREE INTERCEPTORS system are a great first choice as they are already installed on luxury and quality units (all Class A yachts in general), if the manufacturer does not offer it as an option, it would leave me very perplexed about the sophistication and modernization of the boat, unless of course it is a VALUE BOAT.


And why not go for the top.. The stabilization fins (FINS type) still offered by HUMPHREE must be added. They are available for boats from 45 ft to 170 ft.

Interceptors operate within a specific speed range, while fins work perfectly at anchor (thus at a standstill) as well as in cruise mode. However, in cruise mode at a speed of more than 25 KN, their efficiency decreases rapidly. But at low speeds, the combination of the two systems will be at its maximum. Both systems will work together.

The effectiveness of fins have been known for a very long time, but in general they are installed only on large yachts over 80 and 90 feet.

Of course, they are outside the hull while the gyroscopes are installed inside the boat.

But, if you currently have a boat that doesn’t have a stabilization system, here are some relatively easy-to-install alternatives at a lower cost than installing a gyroscope.

You have to compare the installation costs between your fins and a gyro. There is a type fin for every boat size just like the gyroscopes. I confess that for a yacht less than 90 feet, if placing a new order, I would probably choose a gyroscope, especially for a semi-displacement hull or if you prefer to be able to reach 26-33 kn.


Here are the advantages of stabilization fins depending on the manufacturer:

Stabilization at anchor and cruise

Help to reducing anchor slippage

Can be used without a generator

Minimum generator energy consumption

Light and compact

Above photos : Humphree fins intstalled


When both systems are installed on board (Interceptor – Fins):
Stabilization of the roll at all speeds
Stabilization of pitching at cruise
One system, one provider

In conclusion
Also and most importantly, it is necessary to entrust the installation of these systems to qualified and competent professionals…
Don’t hesitate if you have any topics you would like additional information, the members of the team will be happy to investigate.

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