The rendezvous problem between autonomous vehicles is formulated as an optimal cooperative control problem with terminal constraints. A major approach to the solution of optimal control problems is to seek solutions which satisfy the first order necessary conditions for an optimum. Such an approach is based on a Hamiltonian formulation, which leads to a difficult two-point boundary-value problem. In this paper, a different approach is used in which the control history is found directly by a genetic algorithm search method. The main advantage of the method is that it does not require the development of a Hamiltonian formulation and consequently, it eliminates the need to deal with an adjoint problem. This method has been applied to the solution of interception and rendezvous problems in an underwater environment, where the direction of the thrust vector is used as the control. The method is first tested on an interception chaser-target problem where the passive target vehicle moves along a straight line at constant speed. We then treat a cooperative rendezvous problem between two active autonomous vehicles. The effects of gravity, thrust and viscous drag are considered and the rendezvous location is treated as a terminal constraint.