and water, have features that delay or control the onset of lift-induced drag, flow separation, and stall (see Bird flight, Fin, Airfoil, Placoid scale, Tubercle, Vortex generator, Canard (close-coupled), Blown flap, Leading edge slot, Leading edge slats), as well as Wingtip vortices (see Winglet). Lifted ability in air and water The weight a foil can lift is proportional to its lift coefficient, the density of the fluid, the foil area and its speed squared. The following shows the lifting ability of a flat plate with span 10 metres and area 10 square metres moving at a speed of 10 m/s at different altitudes and water depths. It uses the lift at an altitude of 11 km as a datum to show how the lift increases with decreasing altitude (increasing air density). It also shows the influence of ground effect and then the effect of increase in density going from air to water. height 11 km: lift 1.0 (datum for comparison) 5 m 3.4 in ground effect 4.1 water surface-planing 1,280 just submerged 1,420 depth 5 m 2,840 10 km 2,860 See also Aircraft Bilgeboard Boomerang Centerboard Chord (aircraft) Coanda effect Diving plane Drag coefficient Flipper (anatomy) Fluid dynamics Formula One car Keel (hydrodynamic) Lift coefficient NACA airfoil Propeller Sail (aerodynamics) Skeg Spoiler (automotive) Surfboard fin Wing References External links Lift from Flow Turning What is Lift? Bernoulli and Newton Effect of Shape on Lift Incorrect Lift Theory Penguin can fly thresher shark swim towards scuba divers Swimming with Wild Dolphins Bird Flight II Fluid dynamics Aerodynamics