Abstract: A system for the culture of mollusca especially oysters or for collecting mollusca larvae in a water stretch. This system is characterized by the presence of a source of gas under pressure, an inflatable and deflatable floatation device, a conduit connecting the gas source to the floatation device, a mechanism for the introduction of gas under pressure into the floatation device in order to inflate it and for the removal of gas from the floatation device in order to deflate it and fastenings associated with the floating device attaching the latter to a grid constituted of a three dimensional grid type arrangement of culture baskets or of a group of mollusca larvae collectors.