The Summary of Corrections is issued as a supplementary publication for the Notice to Mariners Corrections and provides accurate safety information based on the latest unclassified nautical and navigational charts published by U.S. Government using both domestic and foreign sources.
The NTM corrections incorporate both NOS and NGA charts which source information from various publications including the nine U.S. Coast Guard Districts. Over 60 countries produce their own Notices to Mariners, which are collated into the Summary of Corrections.
There are five regional Volumes that make up the Summary of Corrections, and they are issued from the date of each chart up to the "Corrected through NTM" volume number. The regions referred to in each Volume are as follows:
Volume 1 — East Coast of North and South America
Volume 2 — Eastern Atlantic and Arctic Oceans Including the Mediterranean Sea
Volume 3 — Eastern Pacific, Antarctica, Indian Ocean and Australasia
Volume 4 — Western Pacific Ocean
Volume 5 — Pubs
The Summary of Corrections includes important data such as changes in channels and hydrographic information, making it a vital publication to have for a vessel library.