According to the local Dutch newspaper Vlissingse Courant dated 21 June 1915 was apparently the Italian navy experimenting with extremely small submarines which were to be taken on board of large warships and to be launched if necessary. The costs of these submarines was just around ƒ 45.000 (Dutch guilders) and they could dive without the usual filling of tanks with water as ballast. This diving was done with little metal plates Venetian blind shaped fitted out at the side of the submarine and controlled with a handle inside the submarine. Their crew consisted of just two men.
