Lattice Boltzmann (LB) is a relatively new method to solve hydrodynamicand other problems that are usually described by systems of nonlinearpartial differential equations. Starting point of LB methods is anartificial microworld on a lattice with dynamics obeying certainconservation laws (mass and momentum in the case of hydrodynamics).The corresponding partial differential equations which describe themacroscopic behavior of the system can be derived by a Chapman-Enskog(multiscale) expansion. After introducing the principles of LB methodsa simulation of ocean circulation will be presented. Finally I willdiscuss advantages and disadvantages of LB methods, open questions andfuture perspectives.