Chart correction N20/23 — chart 94218
94218 6Ed. 08/11/12 LAST NM N13/23 N20/23 Add Depth 1.6 meters, blue tint, and enclosing depth contour (2-meter) centered 31°23′35.4″N 121°35′48.6″E (See N51/20) (CHN CH 13179)
Source: NGA U.S. Notice to Mariners · edition: 6Ed. 08/11/12
Reference information — always verify against official Notices to Mariners before navigation.