Throughout the whole time of our existence on the Earth, we were able to examine only 5 to 7% of the sea bottom. It’s much worse in the case of the oceans because scientists estimate that we have explored only 1% of them. Our poor orientation in the depths is resulting mainly from the physical limitations. A human being cannot breathe under the water and time that we can spend under it is limited. The next reason is the enormous pressure at the bottom of the ocean. Technical limitations are also stopping us, however, with years passing we are finally able to overcome some of them. Who knows? Maybe someday we will know more about seas and oceans.