The main well-known advantage of ships with small water-plane area is better seaworthiness. But the shape specificity defines some specificity of all technical and exploitation xharacteristics. The specificity defines some advantages and disadvantages of such ships - in dependence from the ship purpose sea of operations possible restrictions of the main dimensions. The avdantages must be rationally applied and disadvantages must be restricted by rational designing by the proposed special algorithm. The specificity is discribed by the showm book: ship types shapes hydrostatic seakeeping performance controllability strength designing. Two examples of the proposed new ships are shown.