How do Submarines help scientists?

Submarines help scientists by going to the lowest possible depths of the ocean. Humans aren't built for that, as we cannot stand the intense pressure due to the depth. Submarines can go as low as they need AND sustain human inside them. They are wonderful and very helpful. Submarines are helpful to Scientist so they can explore the great depths of the oceans, seas etc. It helps them find out how the sea creatures live under water and what types of sea creatures live underwater. It also helps them to where they can learn about new species of sea creatures. So that is why submarines are so helpful to scientist