The ocean is so huge that we have barely scratched the surface when it comes to exploration. Indeed, the ocean represents 70% of our planet and we explored only 5%, so 65% of the land has not been explored until now and that means that the topographic maps of Mars , Moon and Venus are more advanced than that of the earth. The reason we saw so little of our oceans is extremely difficult to get there. In the deep ocean it is almost impossible to survive without specialized equipment designed to withstand pressure differences and excessive temperature.
