The Underwater Sound Reference Division (USRD) of the Naval Undersea Warfare Center (NUWC) Division Newport maintains an open water facility at Bugg Spring in Okahumpka, Florida (approximately 8 kilometers southwest of Leesburg). This is a prime facility for calibration of submarine and surface ship tactical towed arrays, and is among the quietest Navy open water facilities. Bugg Spring has an ambient noise level below sea state zero and has no recreational boating noise. Dense vegetation surrounding the spring and its somewhat isolated location in a rural area contribute to the low noise levels in the spring. Low reverberation allows measurements down to 5 Hz. There is minimum aquatic life interference. It is the only facility of its kind with year round warm weather.
The spring itself is funnel shaped with a top diameter of approximately 130 meters and sloping walls at roughly 45 degrees to the neck of the funnel. The neck of the funnel is a right elliptical cylinder 30 meters high with major and minor axes of 60 meters and 30 meters, respectively. The hard bottom is relatively flat, sloping approximately 0.5 meters from one end of the test well to the other. The bottom is covered with 3.5 meters of silty sludge-like deposit. The depth to the hard bottom in the vicinity of the test wells varies from approximately 53 meters at the walkway end of the test well to approximately 53.5 meters at the far end.
Hydrographic chart of Bugg Spring showing 3-D view of shape and depth to 50 meters, and position of the testing platform.
Discharge from the spring averages about 0.4 cubic meters per second or about 35,000 cubic meters per day. Though this is a considerable amount of water, the volume of the spring is of such magnitude that there are no significant currents in the spring to interfere with the acoustic measurements. It is estimated that the water in the spring "turns over" about once a week. The inflow and discharge of the spring remain quite constant with time so that the level of the surface of the spring varies only about 0.5 meters.
Water temperature in Bugg Spring (below about 5 meters) is a constant 22 degrees Celsius year round. Measured sound speed in the spring is 1488 meters per second at a depth of 15 meters.
The table below provides a description of the usual capabilities of the Leesburg Facility. Those with special requirements that appear to exceed these capabilities should consult with USRD personnel for further information regarding their special materials handling and test requirements. For example, mobile crane service can be obtained locally on a rental basis, floating crane platforms can be positioned almost anywhere on the surface of the spring compatible with the test requirements. The signal frequency range and power capabilities may at times be modified if feasible.
Click here for a large image of the Rotator Shaft
For questions or assistance in obtaining measurement services, please contact the Leesburg Facility Head at: