Oceanography during this period consolidated into an integrated, cross-disciplinary science that fused physics, chemistry, and biology to explain ocean processes. Investigations focused on the optical properties of seawater to understand daylight penetration and energy balance, chemical oceanography and nutrient cycling to map productivity and biogeochemical fluxes, and physical oceanography emphasizing current dynamics and shelf-scale circulation. Simultaneously, studies of marine biology and plankton distribution linked oceanographic conditions to energy flow and ecosystem structure, while sediment transport and coastal sedimentology illuminated shoreline processes and coastal evolution. Influential Works: Notable breakthroughs spanned momentum transfer, large-scale circulation, and cross-disciplinary synthesis. The layer of frictional influence in wind and ocean currents (1935) introduced the boundary-layer concept for air–sea momentum transfer, enabling drag estimates; A study of the circulation of the western North Atlantic (1936) clarified Gulf Stream dynamics and deep-water exchange; The hydrology of the southern ocean (1937) mapped water masses and overturning; The Oceans, Their Physics, Chemistry, and General Biology (1943) provided a comprehensive synthesis; Phytoplankton periodicity in Antarctic surface waters (1942) revealed seasonal patterns linked to light and nutrients, shaping later polar ecological research.