1. Member States shall ensure that passenger navigation experts and liquefied natural gas experts carry either a Union certificate of qualification issued in accordance with Article 11 or a certificate recognised in accordance with Article 10(2) or (3).
2. By way of derogation from paragraph 1 of this Article, certificates held by persons involved in the operation of a craft, issued or recognised in accordance with Directive 2008/106/EC, and therefore in accordance with the STCW Convention, shall be valid on sea-going ships operating on inland waterways.