Hi Mihir,

There are various broad areas of Marine or Maritime Engineering such as handling operations and functional capability of equipments, research related to water resources, construction and maintenance of ships or sailing vessels. 

Basically, there are 4 themes in Marine Engineering. These are:

-Engine Department

-Deck Department

-Research Engineering

-Marine Management

The above are the various branches of Marine Engineering. Although, marine engineering is itself a field consisting of all the above components.

Hope you will find this information helpful!