Abstract
Marine conservation scientists and managers working in the tropics need bathymetric data, yet there exists no relatively simple and inexpensive system to derive them. We designed a system to produce bathymetric maps in 0–1,000 m water depth in less time, with less cost, and with less effort than any other system available. The system uses Landsat TM imagery to guide the collection and visualization of depth soundings obtained with a commercially available fish finder/GPS on a small boat. ArcGIS is used for interpolation and data display. The system was used to map two reef fish spawning aggregation sites in Belize and may be useful for shelf-edge mapping in other tropical locations.