Few functional changes have occurred in the sirenian auditory periphery since the Eocene. Maneuverability in yaw and pitch maximized by placing both CG and CB, as well as greatest concentration of mass, close to the middle of the animal's length. Skeletal ballast concentrated in thoracid region. Steering organs should be close to front and back ends to produce maximum turning moments. Forward Trim angle greater in infants.
Adults have horizontal trim.