The Acrylic Shells were the basis for the circular shape of the 2004 AUV. In the design phase, it was noted that symmetrical shells could be fabricated using free-form techniques for a few hundred dollars. Custom shells using blow molding techniques could easily soar into the thousands. The shells were generated using Solid Works and the files were sent to California for fabrication. The shells provide the AUV with a level of hydrodynamics, and more importantly drag symmetry. By having a similar drag coefficient around the AUV, the control algorithms can be simplified and the idea of having a front and back, left and right side of the vehicle become less important. This helps with the ultimate goal of moving the vehicle using a combination of vectored thrusts without the need to rotate the vehicle.