Is there a chance to have a job in the maritime field knowing that I am a deck officer on bord merchant ships.?

Yes,there is always an opportunity for you be it in government or private sector.Every country in the world having beaches do have a body or agency looking after their respective maritime field,protecting it from intruders or pollution etc .In private sector there is also an opportunity especially in O&G industry if one requires more challenging working einvironment.

In short,there is always an opportunity unless we just satisfied what we have now  but later regret till our grave.

Good luck