You dont say where in the world you are or live or which country you earned your Degree in.
I would suggest the ROV industry is not the best place for your qualifications, Subsea Engineer or similar working/designing subsea equipment would be a better opportunity for you.
I have always thought that a Degree is of no use in getting a job in ROV operations. Someone with a degree can tell you the square root of an orange, but the cannot peel it. Degrees do not teach you to fault find, to solder, to do practical work. HNC level is best high level for qualifications into the ROV industry (operationally as opposed to work with an ROV manufacturer where it would be of use).