and v is the volume of water displaced or the volume of the vehicle 10 in order for the vehicle 10 to stay underwater it needs to have a higher mass per volume than water since the prototype vehicle weighs two kilograms the volume would need to be less than the volume of two kilograms of water two kilograms of water has a volume of 2000 cubic centimeters or 122 cubic inches if the vehicle volume was to exceed this volume it would be less dense than water furthermore the weight of the vehicle 10 is not limited to two kilograms and could be either more or less in addition the vehicle 10 may be scaled to either a larger or lesser size depending on payload requirements to further enhance the operation of the vehicle 10 the configuration of the body 20 may be varied fig5 illustrates a vehicle 10 u2032 in accordance with an alternative embodiment of the invention in this embodiment the vehicle 10 u2032 again includes a body 20 u2032 a frame structure 30 u2032 and a plurality of propeller assemblies 40 the body 20 u2032 has a spherical configuration which tends to provide a stronger pressure vessel and which also helps to minimize drag and to be less susceptible to side forces the frame structure 30 u2032 includes arms 32 which are sealingly connected to openings 25 in.