Squat and Interaction

Question 1

What is squat?

Answer 1

• Squat is the hydrodynamic effect which causes a reduction in buoyancy
• As the vessel moves through the water it displaces the water around the ship this creates an area of low pressure under the ship, leading to a reduction in buoyancy
• THIS EFFECT IS MOST CRITICAL WHEN THE DEPTH OF WATER IS LESS THEN TWICE THE DRAUGHT

Question 2

Signs of Squat and how to reduce it?

Answer 2

• Render the rudder less effective
• Vessel takes a sudden sheer to starts to vibrate
• Reduce effect by reducing your speed

Question 3

What is Interaction?

Answer 3

• Vessels produce positive pressure at the bow and at the stern and negative pressure along the side.
• In narrow channels and shallow water vessels should be aware of these interactions and helmsman apply counter helm as required