Bluefin Robotics Corporation performed) a concept design study for a new ONR program to develop a Vertical Towed Body (VTB) for acoustic arrays. The work described here involved gathering preliminary requirements for the VTB from the government and various vendors. This information was used to create a concept structural design for the VTB suitable for hydrodynamic analysis. The concept underwent three major revisions. The long term goal is to design, build and test the VTB. The body will then be demonstrated to ONR.