Can a person with a defibrillator work as a captain on a suply boat?

welll i had a defibriilator put in, because my heart was only working 60% well since ive gone back now my heart is working 80% but i was told that i wasnt aloud to do that line of work i was a captian on a suply boat. well i was wondering if anyone new the facts on it. i have never had a heart attack. they just said i needed it for incase i was to have a heart attack it would revive me. since i got it i havnt been able to go back to work im still waiting on a waver to go back from the coast goard. srry for the bad typo in a hurry.