It's in Alaska Polar Sterographic projection, and ready to support Energy, Fisheries, Shipping, Tourism, Ocean Science, Sea-level Rise, Ports, and any other high- latitude projects... A New Level of Cool: The Arctic Ocean Basemap | ArcGIS Blog
Have you also seen the Oceans Resource Centre page. You can search through a gallery of resources such as basemaps, products, data models, tools and more related to oceans and science.