Contrary to landmasses, oceans are extensive in both area and volume. Ninety-seven percent of the earth's water, and 70% of its surface area are consumed by oceans and their associated networks. To be more succinct, dimensions of this size manifest a selection of places for porifera to inhabit. Ever since their appearances as the earliest Metazoans, in the Precambrian (Vendian) age, porifera have represented a substantial percentage of the ocean's populations.

However, the areas of the ocean itself are diverse in relative comparison to porifera. From any point in the world, the ocean will always be different than from any other point in the world. Throughout the ocean world, there are features such as trenches, subductive plate faults, canyons, shelves, and others that are ideally suited for porifera, depending upon characteristics.

Currently, porifera may be delineated between two basic, easy to understand categories for porifera in marine waters. Shore and shallow water dwellers constitute one group. In reference to ocean features, these are shore areas and continental shelfs. The other group are deep sea and abyssal dwellers. These habitats may extend to depths of seven thousand meters or more.

Within each of these areas, sponges reside at different depths. The table below features listing of different depths that sponges are known to inhabit in reference to the sponges. While not a complete listing, it should give a general idea: