The Science behind Yacht Stabilizers

The Science

Technological Leadership In Yacht Motion Dampening

SEA LEGS* YACHT STABILIZERS:
Setting a New Standard In Motion Control

The Difference is in The Design
Conventional roll-fin stabilizers only dampen vessel roll. Sea Legs unique motion control stabilizer systems control roll, pitch and yaw underway and, more remarkably, while at anchor.

Sea Legs uses twin fiberglass T-foils to sustain comfortable motion control. The vertical foils produce a lever action at the transom, which reduces roll and yaw motion, while the horizontal foils act to passively dampen pitch and roll.

The Theory Behind Sea Legs* Stabilizers

Sea Legs transom-mounted stabilizers were designed to create a lifting force that produces a rolling motion opposite that created by the sea, thereby counteracting the rocking waves. The key to this design is based on modern aircraft technology. Sea Legs control the motion of your boat through the water the same way an airplane tail section controls aircraft pitch and yaw, using strategic twin T-foils. These foils induce a lever action at the transom by utilizing lift forces generated by their own aerodynamic shape, to dampen yacht movement around the pitch, roll and yaw axes.

At Anchor

The T-foils work in a completely different way. As the boat rolls to one side, the horizontal section of the T-foil acts to create a high pressure area below the foil to induce drag. This is similar to a swimmer using his hands to stabilize body position while stationary in a pool. At the same time the opposite foil creates pressure above its foil to induce drag as well.

When hydraulic power is taken from the generator, power is available when the main engines are otherwise secured at anchor.

The Science

Single Foil View

Swiss physicist Daniel Bernoulli discovered that the difference in fluid velocity above and below a foil surface create a pressure variation. The result is lift.

How the T-foil works

The vertical surfaces of Sea Legs T-foils generate lift, which dampens roll and yaw. The horizontal surface produces lift which dampens roll and pitch. With this design, the entire T-foil works to reduce uncomfortable motion, with or without hydraulic control.

The Comfort of Digital Control

In active mode, the amount of roll generated by sea condiitons is sensed by a solid-state motion sensor. This sensor sends a signal to the Sea Legs digital hydraulic control system. The system directs hydraulic actuators to move in opposing directions, like aircraft ailerons, at just the right angle and velocity to counteract roll. Simultaneously, the engineered shape of the T-foils passively controls pitch buffering and yaw. This continuous process produces the smooth ride you experience on a Sea Legs-equipped yacht.

Installing Sea Legs Yacht Stabilizers