Present study consists the effect of variation of the vehicle length on the hydrodynamic forces and moments of axisymmetric underwater vehicles due to angle of attack. Five different vehicle lengths are used for this study (L/D varying between 10 and 15) by experimental, numerical and empirical methods. Experimental investigation is done in a tow tank using a VPMM. Numerical analysis is carried out using commercial CFD code Fluent 6.2. The empirical estimation is based on method suggested by Allen & Perkins. Results show that the linear coefficients vary linearly with L/D, while the nonlinear coefficients vary nonlinearly with L/D for the range tested.