A small boat-towed profiling vehicle for coastal water quality assessment

Extensive data collection is required to assess environment characteristics. Traditional observing methods cannot offer the flexibility and cost effectiveness needed for extensive monitoring and water quality assessment in coastal areas where important health and economic involvements are present (such as aquaculture and tourism). At the end of the 20th century, the authors designed and tested various vehicles to perform coastal and offshore monitoring including T-Fish and Sarago that needed to be towed by a 15-20 m vessel. As a part of the MFSTEP programme (EU FP5) a new device was conceived and built for pelagic use, the SAVE (Sliding Advanced Vehicle), able to perform continuous profiles of physical and optical measurements on the top 200 m of the water column. The original system consisted mainly of a depressor, towed at a fixed depth, using a cable on which the main unit slides. Both the depressor and the sliding unit could be equipped with various kinds of sensors. The new goal was to create a coastal version, to be towed from small boats. A first prototype of this kind was funded among the activities of the SAM project (Italian Ministry for Scientific Research) at the start of the millennium, so clarifying the problems occurring in coastal areas, with low depths and medium length (15 m) boats. A second smaller prototype is now under development and test, able to be towed by a very small (8-10 m) boat, like those commonly used ion aquaculture plants, and also fitted with modular water samples for bacterial or chemical determination.