Device for controlling an underwater vehicle, wherein the underwater vehicle comprises at least a front hydroplane and at least a rear hydroplane, wherein the underwater vehicle comprises at least a first ballast tank and at least a first trim tank and at least a second trim tank, wherein the controlling device comprises means for actuating the at least one front hydroplane, the at least one rear hydroplane, the at least one first ballast tank, the at least one first trim tank and the at least one second trim tank, characterized in that the device is configured to implement a first operating state and to implement a second operating state, wherein in the first operating state the device automatically implements a method for determining hydrodynamic coefficients and in the second operating state it controls the underwater vehicle based on a predefined course, wherein in the second operating state the hydrodynamic coefficients determined in the first operating state are used, wherein the method for determining hydrodynamic coefficients comprises the following steps: a) acceleration-free travel with an even keel at a constant depth and at a first first speed and a first first trim position, b) acceleration-free travel with an even keel at a constant depth and at the first first speed and a second first trim position, c) acceleration-free travel with an even keel at a constant depth and at a second first speed and the first first trim position, d) acceleration-free travel with an even keel at a constant depth and at the second first speed and the second first trim position, e) acceleration-free travel with an uneven keel at a constant depth and at a first second speed and a first front hydroplane position and a first trim tank filling, f) acceleration-free travel with an uneven keel at a constant depth and at the first second speed and a second front hydroplane position and the first trim tank filling, g) acceleration-free travel with an uneven keel at a constant depth and at the first second speed and the first front hydroplane position and a second trim tank filling, h) acceleration-free travel with an uneven keel at a constant depth and at the first second speed and the second front hydroplane position and the second trim tank filling, i) acceleration-free travel with an uneven keel at a constant depth and at a second second speed and the first front hydroplane position and the first trim tank filling, j) acceleration-free travel with an uneven keel at a constant depth and at the second second speed and the second front hydroplane position and the first trim tank filling, k) acceleration-free travel with an uneven keel at a constant depth and at the second second speed and the first front hydroplane position and the second trim tank filling, l) acceleration-free travel with an uneven keel at a constant depth and at the second second speed and the second front hydroplane position and the second trim tank filling, m) determination of hydrodynamic coefficients from the measuring variables determined in the preceding steps, wherein steps a) to l) are carried out in any sequence, wherein step m) is carried out after steps a) to l). a) acceleration-free travel with an even keel at a constant depth and at a first first speed and a first first trim position, b) acceleration-free travel with an even keel at a constant depth and at the first first speed and a second first trim position, c) acceleration-free travel with an even keel at a constant depth and at a second first speed and the first first trim position, d) acceleration-free travel with an even keel at a constant depth and at the second first speed and the second first trim position, e) acceleration-free travel with an uneven keel at a constant depth and at a first second speed and a first front hydroplane position and a first trim tank filling, f) acceleration-free travel with an uneven keel at a constant depth and at the first second speed and a second front hydroplane position and the first trim tank filling, g) acceleration-free travel with an uneven keel at a constant depth and at the first second speed and the first front hydroplane position and a second trim tank filling, h) acceleration-free travel with an uneven keel at a constant depth and at the first second speed and the second front hydroplane position and the second trim tank filling, i) acceleration-free travel with an uneven keel at a constant depth and at a second second speed and the first front hydroplane position and the first trim tank filling, j) acceleration-free travel with an uneven keel at a constant depth and at the second second speed and the second front hydroplane position and the first trim tank filling, k) acceleration-free travel with an uneven keel at a constant depth and at the second second speed and the first front hydroplane position and the second trim tank filling, l) acceleration-free travel with an uneven keel at a constant depth and at the second second speed and the second front hydroplane position and the second trim tank filling, m) determination of hydrodynamic coefficients from the measuring variables determined in the preceding steps,