Before revision: Most of the cruises are completed by United States, United Kingdom, Japan, Canada, Germany and Spain Background During 1872 and 1876, Challenger expedition started the modern marine survey and marked the foundation of Oceanography .
After revision: Most of the cruises are completed by United States, United Kingdom, Japan, Canada, Germany and Spain Background During 1872 and 1876, Challenger expedition started the modern marine survey and marked the foundation of oceanography .