Diver Dynamics in matlab

mansoor.aiesecHey i have a problem, I have to simulate a lanewalk program in matlab to show the position of a marine vessel in the inertial frame of reference after integrating the velocity of the marine vessel.
Please help me out with the program. thanks.

basically theres an external current acting on the marine vessel as a result of which instead of tracing his line of sight he reaches a slightly deflected destination at an angle psi..