Abstract: A submersible unit having thrusters for changing a diving position based on a total work quantity, which is the sum of a first work quantity and a second work quantity. A proportional controller generates and outputs the first work quantity based on a difference between a position quantity indicating a desired target diving position and a diving position. A network controller uses a neural network data processing system to learn movement characteristics of the submersible unit based on the first work quantity and a diving position sampled over a plurality of times. The network controller generates a second work quantity using control coupling coefficients learned by minimizing an evaluation quantity determined from a difference between the learned movement characteristics and target movement characteristic values.