All three Districts of MEBA had radio officers.
MEBA District 1 is just marine engineers with a handful of Radio Officers who worked on the Liquid Natural Gas (LNG) ships.
MEBA District 2 originally was Great Lakes Engineers but Ray McKay started adding Deep Sea Engineers, Mates and Radio Officers and made deals with companies to do a top-to-bottom manning with arrangements with Seafarers International Union (SIU) who supplied unlicensed seamen, engine room, and steward's department workers.
ROU is District 3 Marine Engineers Beneficial Association and was all radio officers.