marmap - Import, Plot and Analyze Bathymetric and Topographic Data

Import bathymetric and hypsometric data from the NOAA (National Oceanic and Atmospheric Administration, <https://www.ncei.noaa.gov/products/etopo-global-relief-model>), GEBCO (General Bathymetric Chart of the Oceans, <https://www.gebco.net>) and other sources, plot xyz data to prepare publication-ready figures, analyze xyz data to extract transects, get depth / altitude based on geographical coordinates, or calculate z-constrained least-cost paths.