Career

According to your question, it looks like you want everything quick and fast. Well, chemical engineering is a good option. While applying for private institute you have yo be careful have a research regarding placement. If you get selected in campus interview then there is no need for you to run here and there for a job. In case you don't get placed then you have options like Reliance, Asian paints, IOCL, Shell, Total, Petrobras, etc. You have to apply on your own which is a bit long process. You can get a job in these companies if vacancies are available. As competition in the chemical engineering field is pretty high. So, be prepared and work hard.
Best of luck.

Shipping and Marine are two different career streams. By shipping, we mean that you are getting into the logistics side but why Marine you are becoming the resource that executes work. From the engineering side, run the ships, manage the day to day shipping work, repairs engine, turbines etc. You can do a Masters in Marine Engineering as you've already done mechanical and get into marine life. This life looks lucrative in terms of money but has other consequences like you have to spend 6 months at home and 6 months on the sea. On the contrary in the shipping industry, you can look at jobs in Logistic companies where you can be a planner, scheduler or manager handling all the shipping assignments, etc. You can also look at roles and customs and excise that are somewhat linked to the shipping sector.