As you want to get the details of career after ME or M.Tech Marine Engineering so here it is for you:

M.Tech. Marine Engineering Job Types

Defence Engineer

Marine Engineer

Maritime Engineer

Naval Ship Engineer

Systems Engineer

Faculty - Marine Engineering

General Manager Marine Defence - Export Business Development

Contracts Advisor Marine Dept

Marine Navigation Systems Specialist

Marine Engineer

Sales & Marketing Executive

Advance Course in M.Tech. Marine Engineering
Ph.D. (Marine Science)

After completing M.Tech. (Marine Engineering) you can become:
Marine Engineer

Some of its specialized fields are: -

Maritime Commerce

Marine Refrigeration

Command And Control System

Weaponry And Weapon Systems

Navigation Systems And Equipment

Marine Renewable Energy Research

Autonomous Underwater Vehicle Research

Information, Communication Systems and Equipment

Offshore Extractive and Infrastructure (Cable Laying)

Some job titles: -

Pumpman

Harbor Master

Chief Engineer

Third Engineer

Fourth Engineer

Second Engineer

Marine Engineering Officers

Junior (Fifth) Engineer

Navy Weapon Engineering Officer