SIST EN ISO 12217-2:2026

This document specifies methods for evaluating the stability and buoyancy of intact (i.e. undamaged) boats. The flotation characteristics of boats susceptible to swamping are also encompassed. The evaluation of stability and buoyancy properties using this document will enable the boat to be assigned to a design category (A, B, C or D) appropriate to its design and maximum load. This document is principally applicable to boats propelled primarily by sail (even if fitted with an auxiliary engine) of 6 m up to and including 24 m hull length. However, it can also be applied to boats less than 6 m if they are habitable multihulls or can be applied 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, this document includes assessment of susceptibility to inversion, definition of viable means of escape and requirements for inverted flotation. This document excludes: — inflatable and rigid-inflatable boats covered by the ISO 6185 series, except for references made in the ISO 6185 series to specific clauses of the ISO 12217 series; — gondolas and pedalos; — surfboards including sailing surfboards; and — hydrofoils and foil stabilized boats when not operating in the displacement mode. NOTE Displacement mode means that the boat is only supported by hydrostatic forces. 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.