The survey of Neuchâtel was the first extensive systematic underwater survey of a European lake by remote sensing, the first project to use multiple geophysical systems to discover submerged archaeological sites. This information is to be used in a regional database. Photographs taken in 1921 compared to photos from 1971 show significant site degradation resulting from the dynamic hydrological processes of the littoral zone of the lake. The instrumental detection of Cortaillod-Est and Les Esserts is discussed. Constraints on the work are time, weather, personnel, and equipment. Side scan sonar, microwave radar, and magnetometer were used in the survey. Divers, however, are needed to determine whether the sonar target or magnetic anomaly is of archaeological interest. Extensive lake bottom floral growth prevented use of the sub-bottom profiler the season this work was carried out.