To the OP, traveling for work is NOT the same thing as traveling for pleasure. Work, and the purpose for being there will always be the first priority. When time and circumstances allow, yes you can “explore”. But you are always mindful of when you have to be back, sober, rested, and be prepared to work. If you are on a steady run and hit the same ports, you can get a feel for those opportunities. If you happened to be in a shipyard while the ship is undergoing repairs, drydocking, etc. you are there to work. If not working, you would likely be sent home.
About the only exception is working on some sort of government contract ship.