1. DETERMINATION OF THE CENTRE OF GRAVITY AND THE MAIN AXES OF INERTIA 

This determination was done on the basis of a finite element model. This model is represented in the figures 1. The total mass of the Shark (prototype 1/3)  was determined analytically to be 13,4 Kg, this corresponds favorably to the mass that was experimentally measured as 12,5 Kg with more or less empty tanks. With its origin in the bow and the system of coordinates as shown in figures 1, the centre of gravity is situated as: 

x = 0,762 m 
y = 0,000 m 
z = 0, 137 m 

The corresponding moments of inertia around  this centre of gravity are: 

Ixx = 0,404 kgm2 
Iyy = 0,9582 kgm2 
Izz = 1,264 kgm2 
Ixy = 0,139 kgm2 
Iyz = 0,097 kgm2 
Ixz = 0,127 kgm2 

In order to determine the stability of the prototype by means of a simulation programme the mass inertia moments must be known, because of their determining influence on the dynamic behaviour of the vehicle. 

Figures 1a, 1b, 1c, 1d, 1e:
finite elements models of the Shark