The reason why some ocean water is more turquoise than others is due to the absorption and scattering of light, with absorption being a larger factor than scattering for clear ocean water. Waters in places like the Caribbean, South Pacific like in Bora Bora, and Greece are shallower and almost free of plankton, causing them to be a specific shade of azure blue. These waters are also usually home to heavier sand and sediment, which churn up less, leaving waters more clear. Additionally, these little slices of paradise tend to experience less "upwelling," which can turn water murkier.