Abstract ISO 12217-1:2013 specifies methods for evaluating the stability and buoyancy of intact (i.e. undamaged) boats. The flotation characteristics of boats vulnerable to swamping are also encompassed. The evaluation of stability and buoyancy properties using ISO 12217-1:2013 will enable the boat to be assigned to a design category (A, B, C or D) appropriate to its design and maximum total load. ISO 12217-1:2013 is principally applicable to boats propelled by human or mechanical power of 6 m up to 24 m hull length. However, it can also be applied to boats of under 6 m if they do not attain the desired design category specified in ISO 12217-3 and they are decked and have quick-draining recesses which comply with ISO 11812. In relation to habitable multihulls, ISO 12217-1:2013 includes assessment of vulnerability to inversion, definition of viable means of escape and requirements for inverted flotation. ISO 12217-1:2013 excludes: inflatable and rigid-inflatable boats covered by ISO 6185, except for references made in ISO 6185 to specific clauses of ISO 12217; personal watercraft covered by ISO 13590 and other similar powered craft; gondolas and pedalos; sailing surfboards; surfboards, including powered surfboards; hydrofoils and hovercraft when not operating in the displacement mode (displacement mode means that the boat is only supported by hydrostatic forces); and submersibles. It does not include or evaluate the effects on stability of towing, fishing, dredging or lifting operations, which need to be separately considered if appropriate.