Have you ever wondered how a sea is different to an ocean? The two are often used interchangeably, but they have many differences. Differences between an ocean and a sea Oceans are bigger than seas. They cover 70% of the planet and have an average depth of 3800m. Oceans are not contained by land. Seas […] The post What's the difference between a sea and an ocean? appeared first on Science Experiments for Kids.