Chart correction N40/21 — chart 94216
94216 9Ed. 8/4/12 LAST NM N36/21 N40/21 Substitute Depth 3 meters for stranded wreck 31°05′08″N 121°58′58″E Depth 7.6 meters Obstn [K41] for depth 6.9 meters Obstn 31°02′11″N 122°19′51″E (See N18/21) (28(981, 982)21 Tianjin)
Source: NGA U.S. Notice to Mariners · edition: 9Ed. 8/4/12
Reference information — always verify against official Notices to Mariners before navigation.