As a vessel owner operatoror captain, with responsibility for crew members, there are some issues you need to be aware of.
A key part of the Maritime Labour Convention is that employees of Seafarers will be subject to periodic inspections to ensure compliance. Accordingly, it is imperative that the employment of crew takes place in a manner that is fully MLC compliant and in line with legal requirements.
EU regulation EC/883/2004 which regulates amongst other things, social security contributions for mariners employed on EU flagged yachts, requires that seafarers who reside in the EU/EEA/Switzerland (citizens or not) employed on an EU flagged yacht must be insured according to the law of the EU flag State, and in that State.
The only exception lies in the case where employer and employee reside in the same Member State; the seafarer must be affiliated in that State for social security.