The Charente Maritime coast, in central western France, is the most important area for oyster and mussel production in Europe. High density, in this restricted intertidal area, induces low growing rate and socio-economic difficulties. One of the possible solutions is to shift some oysters from intertidal area to submerged areas. Bathymetry, sedimentology, hydrodynamism, fisheries and administrative rules are some conditions which are considered to establish the better selection of potential zone. The successive steps of setting up the prototype of GIS are presented: digitized traditional data from charts, extracted data from grid models (hydrodynmaic model), merging of thematic covers, proposal of favorable areas. The results are discussed especially on the points where spatial analysis methodologies have to be improved : crossing methodologies between grid and vector formats and aggreagation of layers. Some ways of research are presented, particularly the improvement of some techniques issued from artificial intelligence (possibilities theory, fuzzy logic).