Why does my boat sink with a Buoyancy Component?

Buoyancy needs at least 3-4 Pontoons distributed around the bottom of the hull. A single pontoon at the center isn't enough. Add Pontoons in the component's Pontoons array.

Pontoons radius matters?

Yes — larger radius produces more lift. Tune to balance against the hull mass. Too small: sinks. Too large: bobs comically.

Does the Water Body need collision?

For physics-driven buoyancy, the Water Body Actor must have its physical surface enabled and the Buoyancy plugin loaded. Verify collision profile lets your boat's pontoons sample the water surface.

Fix: Unreal Water Buoyancy Component Not Floating

Quick answer: Add 4 Pontoons to the Buoyancy Component, distributed around the boat’s bottom. Tune radius to balance lift vs hull weight. Confirm the Water plugin is enabled and Water Body has Buoyancy enabled.

Boat actor with one Buoyancy Component sinks immediately. Single pontoon doesn’t provide enough volume. Distribute pontoons around the hull.

The Symptom

Boat falls through water surface or doesn’t float at expected depth. Single pontoon at root won’t support a meaningful hull mass.

The Fix

BuoyancyComponent (on boat actor):
  Pontoons:
    [0] FrontLeft   (Relative Location: -100, -100, 0),  Radius 100
    [1] FrontRight  (Relative Location: 100, -100, 0),   Radius 100
    [2] BackLeft    (Relative Location: -100, 100, 0),   Radius 100
    [3] BackRight   (Relative Location: 100, 100, 0),    Radius 100
  Water Velocity Strength:    1.0
  Buoyancy Coefficient:       1.5

Four pontoons spread across the hull base provide enough lift and natural roll/pitch from displaced water differences.

Plugin and Water Body

Edit → Plugins → Water enabled. Water Body Lake/Ocean actor in scene. Buoyancy queries the Water Body to find surface height.

Verifying

Drop boat into water. Should float at the level where pontoon volume = hull mass. Tilts naturally on waves. Without enough pontoons: sinks.

“Multiple pontoons. Right radius. Plugin enabled. Boat floats.”

Related Issues

For physics constraint jitter, see constraint jitter. For Niagara collision events, see collision events.

Pontoons distributed. Plugin loaded. Hull rides.