IT used to be that those who were engaged and worked as crew onboard ships were denominated simply as seafarers, regardless of position, gender or affiliation. RA 12021 otherwise, known as the Magna Carta of Filipino Seafarers instituted two categories of Filipino seafarers: a) domestic seafarers and b) overseas seafarers.
Without the need to refer to the law, one can conclude that the classification of Filipino seafarers would refer to the area of operation of the ship to which they are deployed, either in domestic or international waters.