IPA: /oʊˈʃənəˌɡræfər/
KK: /oʊˈʃənəˌgræfər/
A person who studies the ocean and its various aspects, including its physical, chemical, and biological properties.
The oceanographer collected samples from the deep sea to analyze marine life.
Oceanographer → It is formed from "ocean" (from Greek "okeanos", meaning the great sea) and "-graph" (from Greek "grapho", meaning to write or describe). An oceanographer is someone who writes or studies the ocean.
Think of someone who 'describes' ('grapho') the 'great sea' ('okeanos') — that's what an oceanographer does.