Question

what was Jacques Cousteau importance in the science of oceanography?

Answer 1

Among many other things, he is the co-inventor of S.C.U.B.A. (Self Contained Underwater Breathing Aparatus).
Who-steau? Cousteau!
Yes, he co-developed (and patented) the Aqualung, which is a very important part of SCUBA diving. He is known to have been an expert on deep sea diving, experimentation, as well as deep sea life and the reasons for the conservation thereof.