The world is constantly seeking new sources of energy to replace the use of coal and fossil fuels to generate electricity. And a strong source of energy from the ocean is one of the hopes of scientists around the world. Ocean energy is an endless renewable energy source for making electricity used for the world. Marine technology was once considered too expensive to be a viable source of alternative clean energy, especially compared to already developed products such as wind and solar. However, with the increased price of oil and the issues of global warming and national security, U.S. coastal sites are looking to add ocean energy to their renewable energy portfolios. This paper gives an overview of ocean energy technologies, focusing on two different types: wave, tidal. It outlines the operating principles, the status, and the efficiency and cost of generating energy associated with each technology.