The Inland Electronic Navigational Charts (IENC) dataset is updated bi-monthly by the US Army Corps (USACE)/Army Geospatial Center (AGC), and part of U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). There is a partial delivery on the 1st and 15th business day of a month. If there is a need for a special chart delivery, occasionally there will be updates outside of the delivery cycle. The charts with data changes are released either as new editions or updates to existing IENCs on a regular delivery cycle. These IENCs were developed from available data used in maintenance of Navigation channels. These vector data, that make up the charts, can be downloaded as a geodatabase here: https://ienccloud.us/ienc/products/files/U37/ienc_master_dataset_gdb/USACE_IENC_Master_Service_gdb.zip. In addition, web mapping services of the feature classes/datasets can be found here: https://ienccloud.us/arcgis/rest/services/IENC_Feature_Classes. Users of these IENCs should be aware that some features and attribute information could have significant inaccuracies due to changing waterway conditions, inaccurate source data, or approximations introduced during chart compilation. Caution is urged in use of these IENCs or derived products for navigation planning or operation, or any decisions pertaining to or affecting safety of vessel operation. Only charts downloaded from the USACE chart server, https://ienccloud.us, and used in an Electronic Chart Display Information System (ECDIS) or Electronic Chart System (ECS), or official government chart books are suitable for navigation.