The Ocean plays a significant role in our lives since the beginning of civilization. It is clear that the scientific study of the ocean is very important in contemporary world. This Handbook is written in simple language covering all disciplines and branches of marine science like marine geology, meteorology, marine environment, marine ecology, marine biology, marine chemistry, marine physics, marine geophysics and fluid mechanics, etc. In this particular publication our effort is to give comprehensive information covering all aspects of ocean and oceanography. We sincerely believe that this handbook will help the readers to understand the subject thoroughly.