How is exploring oceans similar to exploring space?

They're both mostly unexplored and unexplainable

Exploring space and ocean are both similar because they both take a lotof time and money to explore when you are in space you must use a vehicle that is design to withstand extremly low pressures. When you are in the océan you must use a vehicle that is able to withstand very high presures exploring space is easier but more expensive but exploring the ocean is harder and more cheaper