You can get NOAA ENC datasets for free at NOAA ENC® . This site also provides access to an ENC Viewer, which is using ArcGIS Maritime's server extension Nautical Charts Online | Display S-57 & S-63 Encrypted Datasets on the Web. To get global coverage you would need to contact a value added reseller (VAR). You can access a list of them at Current IC-ENC VARs. I would recommend AVCS or Chartworld, depending on your needs. Chartworld also distributes Navionics data, though unofficial ENC data, it still provides great coverage.
What are you looking to do with the data once in ArcGIS? Knowing this would allow me to provide additional details on how ArcGIS and the various extensions can work with either S-57 ENC or S-63 encrypted ENC datasets.