How is exploring oceans similar to exploring space?

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

They're both mostly unexplored and unexplainable