Field experiments were conducted to test ideas for fossil fuel carbon dioxide ocean disposal as a solid hydrate at depths ranging from 349 to 3627 meters and from 8 degrees to 1.6 degrees C. Hydrate formed instantly from the gas phase at 349 meters but then decomposed rapidly in ambient seawater. At 3627 meters, the seawater-carbon dioxide interface rose rapidly because of massive hydrate formation, forcing spillover of the Liquid carbon dioxide from the container. A strong barrier between the liquid carbon dioxide and interaction with the sediments was observed. A pool of Liquid carbon dioxide on the sea floor would expand in volume more than four times, forming hydrate, which will dissolve.