Regulation 1.3
1 If a passenger ship built before 1 January 2009 undergoes alterations or modifications
of major character, it may still remain under the damage stability regulations
applicable to ships built before 1 January 2009.
2 If a passenger ship constructed on or after 1 January 2009 but before the
applicable dates in regulation 1.1.1.1footnote undergoes alterations or modifications of
major character that don't impact the watertight subdivision of the ship, or only have a
minor impact, it may still remain under the damage stability regulations that were
applicable when it was constructed. However, if alterations or modifications of major
character significantly impact the watertight subdivision of the ship, it should comply
with the damage stability regulations in part B-1 applicable when the alterations or
modifications of major character are carried out unless the Administration determines
that this is not reasonable and practicable, in which case the attained subdivision
index A should be raised above the original construction required subdivision
index R as much as practical.
3 Application of MSC.1/Circ.1246 is limited to cargo ships constructed before 1
January 2009.
4 A cargo ship constructed on or after 1 January 2009 of less than 80 m in length that is
later lengthened beyond that limit should fully comply with the damage stability
regulations according to its type and length.
5 If a passenger ship that has been in domestic service only and never issued a SOLAS
Passenger Ship Safety Certificate is converted to international service, for purposes of
the stability requirements in parts B, B-1, B-2, B-3 and B-4 it should be treated as a
passenger ship constructed on the date on which such a conversion commences.