How to start working as mate on offshore vessels

Hello everybody. I am from Bulgaria and till now I have worked as third/second mate mostly on board container ships. Last year I took my chief mate (3000 GT or more) license. My strong desire is to start working as mate on board any of the following offshore vessels- standby/ PSV / AHTS / Seismic / Cable laying. For the moment it looks extremely difficult to get that job. I know that having no service on offshore vessels could be a problem, but nobody was born with experience and everybody started somehow.
Could you advice me how to enter offshore vessels industry. Shall I pass first DP basic/induction course. Do you know any companies for “beginners”:slight_smile: like me?