Lagoon management can be greatly aided by knowing how much sludge is in a lagoon at a given time. As well, knowing the amount of build-up in a lagoon is necessary in order to monitor the effectiveness of sludge management products. But actually measuring the sludge amount can be a laborious and dangerous job. Recently, interest in the use of sonar waves for sludge measurements has increased among the scientific and business community. The University of Georgia’s Department of Biological and Agricultural Engineering decided to develop an air-powered remote controlled airboat. The researchers tested its measurements for various settings of the control panel variables and validated the airboat measurements with reports by a private commercial firm using a similar, but more complicated system. The remotely controlled unmanned airboat was designed and assembled by Pat Harrel, a UGA technician. The 44 inch long and 24 inch wide airboat is equipped with a fish finder sonar unit coupled with a global positioning system (GPS) receiver. The fish finder uses a 200kHz transducer located at the bottom rear edge of the airboat. The airboat is propelled by a gasoline engine driven propeller. Three Teflon bars are installed at the bottom of the airboat to reduce friction while moving over floating debris. The remote control unit has two actuators: one controlled the direction by moving two air wings mounted behind the propeller, and the other controls engine speed. On the airboat, the sonar unit collects the data in the form of a map of the bottom of the lagoon. To record and redisplay this map, the sonar unit also stores information about the speed, position, depth to top and bottom of sludge layer, and other details in a data file. During validation analysis for the data collected by the airboat, the mapping data reported by the private firm was used as reference. The top surface of the sludge obtained from the airboat and that from the private firm are shown in Figure 1. Both surface maps for the top of the sludge looked similar except that the surface map resulting from the airboat data had more spikes on the surface. This non-smooth behavior might be due to the use of a less accurate GPS system with the airboat. The GPS system used by the private firm had accuracy within inches compared to several feet for the system used by the airboat GPS. While the airboat technology for sludge measurement is 15 to 20 times faster and 70 percent less labor consuming, further research is needed to generalize this technology.