The Navy is seeking an inertial navigation system for undersea Unmanned Underwater Vehicles (UUV), but there is not available space, power, or budget to make use of today’s state-of-the-art systems. Cybernet’s Inertial Measurement and Magnetometer Module (I3M) is small, low powered, and low cost – but it does not currently provide the accuracy of state-of-the-art underwater navigation systems. Cybernet is proposing to implement multiple I3Ms in one package, and then use probability theory to reduce the error of the output data. Additionally, we will use the spherical relationship between the accelerometers and magnetometers to improve the heading accuracy. By doing this, we expect to reduce the size, power, and cost of underwater navigation systems used in low power UUVs. The development in this project will be used to improve Cybernet’s I3M product line.