You'll score some points for showing up ready to go that day or the next, being polite and not saying you're ready to be the chief engineer. You may get on that track and have people willing to move you up and help you with training if you've impressed them with your ability to chip and paint, effectively clean a toilet and accurately throw a line. You'll score points for getting up for your watch early, knocking out your dailies and weeklies efficiently and asking for more work. Rinse and repeat. Folks come from all over to work down here, and the prevailing attitude in the offices is that deckhands are a dime a dozen.
The "O" in OS stands for "ordinary," by the way.
Not saying you can't build a great career, but it's not going to happen overnight.