Question

How are the careers of an oceanographer and hydrologist similar? How are they different?

Answer 1

Hydrologist - studies the effects of water on the earth's surface. 
Oceanographer - studies the earth's oceans.
I guess...
Hope this is it....

Answer 2

An oceanographer is one who studies the attributes of the ocean like temperature, waves, currents and tides geology of the sea floor.

And a hydrologist is one who researches the distribution, circulation and physical properties of underground and surface waters.

They both are similar as they both study the chemical property of water.