The document discusses various topics related to marine water. It begins by defining marine water as water that contains living things and notes there are different types of water like salt water, fresh water, and tap water. It then discusses that 97% of the Earth's water is contained in the oceans and seas, which is called marine water, with the remaining 3% making up fresh water sources. Finally, it provides a brief overview of the natural water cycle and how water evaporates from oceans and seas into clouds before falling as rain.