The objective of the paper is to develop a mathematical model for reliable prediction of the dynamic behaviour of a towed modular system against variable ambient conditions. The developed model is a first step towards depiction of tow shape and drag forces acting on the towed system, comprising of a heavy tow cable and an electro active polymer actuated tow fish. Initially, towed module for the presented model is chosen to make it comparable to a previously developed model. Finally, the developed model is validated by comparing its numerical results to a fairly developed finite element code, previously presented in literature. Furthermore, the present study aims to address two important ambient factors, i.e. variant water current and density, in a numerical approach. Finally, similar modelling approach is adopted to predict the tow shape of the towing system, used for the tow fish, and tension exerted by the system on the towing vessel is also depicted.