In order to best generate the design requirements, the conditions under which the UUV will be operating must be defined. Since the expected area of operations is the Chesapeake Bay, this means designing the vehicle to function in both fresh and saltwater environments. This means not only contending with the chemical properties of seawater, but also the different flora and fauna native to the estuary region. Slightly less than 50% of the Chesapeake Bay is under 50ft (6m) deep, 85% is under 30 ft (9 m) deep, and only 26% is deeper than 40 ft (12 m) deep. The primary oyster habitats in the bay are located in waters shallower than 30 ft (9 m) deep.
The water flux experienced in the bay is a sum of tidal motion and of freshwater input from the streams and rivers feeding into it. The underwater currents experienced in the bay are a function of the net water flux into and out of the bay, the basin geometry, and the strength of tidal action. The eastern portion of the bay has a deep and narrow channel, and generally has higher currents than the western portion. Currents induced by wind and water influx are difficult to predict due to their nonperiodic nature; tidal currents are the easiest to predict. Tidal currents in the bay are at their greatest in the mouth, where the ocean meets the bay, with a maximum average value of 1.03 m/s (3.38 ft/s). The average currents reduce to a minimum of 0.13 m/s (0.43 ft/s) in the middle of the bay, then increase slightly upstream to an average maximum of 0.59 m/s (1.94 ft/s) near the Bay Bridge, near Baltimore.
The below picture is a sample NOAA depth chart of the Chesapeake Bay.