NAAMES_MetNav_ShipInSitu_Data are in situ meteorological and navigational measurements collected onboard the R/V Atlantis vessel during the North Atlantic Aerosols and Marine Ecosystems Study (NAAMES). These measurements were collected from November 4, 2015 – November 29, 2015, May 11, 2016 – June 5, 2016, August 30, 2017-September 22, 2017 and March 18, 2018 – April 13, 2018 over the North Atlantic Ocean. The primary objective of NAAMES was to resolve key processes controlling ocean system function, their influences on atmospheric aerosols and clouds and their implications for climate. The ship-based measurements provide detailed characterization of plankton stocks, rate processes, and community composition. Ship measurements collected during NAAMES also characterize sea water volatile organic compounds, their processing by ocean ecosystems, and the concentrations and properties of gases and particles in the overlying atmosphere. Data collection for this product is complete.The NASA North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) project was the first NASA Earth Venture – Suborbital mission focused on studying the coupled ocean ecosystem and atmosphere. NAAMES utilizes a combination of ship-based, airborne, autonomous sensor, and remote sensing measurements that directly link ocean ecosystem processes, emissions of ocean-generated aerosols and precursor gases, and subsequent atmospheric evolution and processing. Four deployments coincide with the seasonal cycle of phytoplankton in the North Atlantic Ocean: the Winter Transition (November 5 – December 2, 2015), the Bloom Climax (May 11 – June 5, 2016), the Deceleration Phase (August 30 – September 24, 2017), and the Acceleration Phase (March 20 – April 13, 2018). Ship-based measurements were conducted from the Woods Hole Oceanographic Institution Research Vessel Atlantis in the middle of the North Atlantic Ocean, while airborne measurements were conducted on a NASA Wallops Flight Facility C-130 Hercules that was based at St. John's International Airport, Newfoundland, Canada. Data products in the ASDC archive focus on the NAAMES atmospheric aerosol, cloud, and trace gas data from the ship and aircraft, as well as related satellite and model data subsets. While a few ocean-remote sensing data products (e.g., from the high-spectral resolution lidar) are also included in the ASDC archive, most ocean data products reside in a companion archive at SeaBass.