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Improve Your Boat's Performance with Automatic Trim Tabs and Interceptors

Humphree Lightning on transomNo matter the design characteristics of your 20-45 foot power boat, automatic trim and stability systems significantly improve boating performance. This blog looks at all aspects of boat performance, how Humphree Lightning enhances acceleration, speed and manoeuvrability and the differences you can expect. 

Why is automatic trim and stability control so important for better performance? 

The design of your boat’s hull includes several characteristics, each of which are design decisions or compromises that affect speed and manoeuvrability. But that’s just the start because your boat never operates constantly in one state. Speed, acceleration, the water surface, wind, and weight distribution are all variable, yet the hull’s design is constant. 

So, the core idea of automatic trim and stabilisation is to create a way to change the boat’s hydrodynamic characteristics in real-time as conditions change. 

Let’s look at the ways that performance is improved. 


How does automatic trim and stabilisation work? 



From the moment your boat starts to move until it’s on the plane, a lot happens. 

Initially, the engine’s thrust causes the bow to rise, which moves the weight back and forces the stern deeper into the water. This compromises the hull’s displacement performance and increases drag. 

As the speed rises, the bow and stern waves generated by displacement cause the boat to sit down in the trough between them. The boat must then climb up to crest the wave to get up on the plane. 

Humphree Lightning helps improve acceleration by creating lift at the stern and lowering the bow. The result is that the boat accelerates up onto the plane significantly faster. The hull’s displacement design is restored, drag is reduced, and less power is needed to climb out of the trough and onto the plane. 

How hydrodynamic lift works



If correctly set up, your boat should plane at speed perfectly. But conditions are never precisely perfect or constant. An uneven water surface, the relative angle of swell, wind direction, and weight distribution all impact performance. 

The effects of this are well known. The bow can pitch up and down, and the boat may roll and steer in certain swells or not be level across the beam. The boat will feel less stable, so speed must be reduced. 

Humphree Lightning answers these variables by constantly applying auto trim to control pitch and roll. The hull’s position in the water is continuously monitored using gyro sensors. This data feeds into the real-time adjustment of the port and starboard interceptors to keep the boat more level and its hull working closer to optimal in all conditions. 

Accelerating speed boat


Handling and manoeuvrability 

Humphree Lightning has another trick up its sleeve called Coordinated Turn. Available as part of the Dynamic Plus and Comfort Plus software upgrade packs, coordinated turn uses the Lightning interceptors to improve handling and manoeuvrability performance. 

One compromise in a boat’s hull design is the dead rise angle of the hull’s V shape. The V shape exists to cut through chop at speed and create a smooth, hydrodynamic shape when operating off the plane in the hull’s displacement mode. However, the sharper the dead rise angle, the more it compromises cornering performance. 

The problem is that when turning, the boat falls over onto the dead-rise angle. The lean induced is almost always far more than the optimum banking required for stable turning. The effect is a wider turning arc, less responsive handling, and less-than-optimal manoeuvrability. 

Humphree Lightning controls this by applying dynamic trim adjustment to the inside interceptor. This reduces excessive banking roll and dramatically improves cornering performance. 

Coordinated turn 

Better performance 

The improvements in performance across acceleration, speed, and handling that Humphree Lightning adds to your boat can’t be overstated.  

Performance is improved by getting up onto the plane faster, controlling the boat safely at a higher speed relative to conditions, and handling more nimbly. 

Contact us today to learn more about fitting Humphree Lightning to your boat.