Applying Forces, independent of Frame Rate?

I’m having problems creating frame rate independent controls for my character, in this case a boat.

I am getting the in put in the Update() and then applying forces to the rigid body in the FixedUpdate.

I’m not sure to ether use Time.DeltaTime or Time.FixedDelta time?

What is the correct way to make the forces applied to the rigid body completely frame rate independent?

For framerate independence you want to use Time.deltaTime in Update() and Time.fixedDeltaTime in FixedUpdate(). It is recommended that you perform Physics operations in FixedUpdate().