Three thousand kilos of hashish would have to be sunk into the sea and then recovered.
it is a method widely used by the mafia in recent times
The octopus gang was a large Dutch criminal organization dedicated to the importation of hashish in the 1990s they already used that method along the coast of Portugal.
yes, the Mexican and Colombian cartels use that method too; in Sicily in recent years it seems that it is also used for cocaine
They maybe using experienced divers at least the Octopus group did.