Dangerous Ground (South China Sea)

The boundary of Dangerous Ground is shown on NGA charts 93044 (NW),^[2] 93045 (NE),^[3] 93046 (most of the SE),^[6] and 93047 (SW).^[7] (The missing portion of the SE is covered by 93048^{[note 1]} and the top corner of 92006.^[5])

The area is described in NGA Pub. 161, Sailing Directions (Enroute) South China Sea and the Gulf of Thailand.^[1] The navigational charts and sailing directions do not completely agree with each other as to the boundary. For example, the Sailing Directions include most of the NW area shown on Chart 93044 as outside of Dangerous ground, but exclude the Reed Bank, which is shown on Chart 93045 as inside Dangerous Ground.

Both publications divide the area into four quadrants - NW, NE, SE and SW:

Chart 93044 – approx. 10–12°N, 113–115°E;^[2] Sailing Directions pp8–10.^[1]

• 1.21 North Danger Reef – northern and western sections
  • North Reef, North Pass, Northeast Cay, Shira Islet, Middle Pass, Southwest Cay, West Pass (N), Jenkins Patches, West Pass (S)
• 1.22 North Danger Reef – southern and eastern sections; Trident & Lys Shoals
  • South Reef, South Pass, Sabine Patches, Farquharson Patches, East Pass, Day Shoal, Iroquois Ridge; Trident Shoal, Lys Shoal
• 1.23 Thitu Reefs and surrounding
  • Thitu Island, Subi Reef
• 1.24 Loaita Bank
  • Loaita Island, Lankiam Cay
• 1.25 & 1.26 Tizard Bank
  • Namyit Island, Gaven Reefs, Sand Cay, Itu Aba Island, Petley Reef, Eldad Reef
• 1.26 West of Tizard Bank
  • Western Reef, Discovery Great Reef, Discovery Small Reef

Chart 93045 – approx. 10–12°N, 115–117°E;^[3] Sailing Directions pp10–11.^[1]

• 1.27 East of Loaita Bank
  • Menzies Reef, Irving Reef, West York Island
• 1.27 Southampton Reefs (East of Tizard Bank)
  • Hopps Reef, Livock Reef
• Northern NE – Reed Bank
  • Nares Bank, Marie Louise Bank
• 1.27 & 1.28 Central NE
  • Jackson Atoll, Nanshan Island, Flat Island, Third Thomas Shoal, Hopkins Reef, Amy Douglas, Hirane Shoal, Hardy Reef
• 1.29 Eastern NE
  • Sandy Shoal, Seahorse Shoal, Lord Auckland Shoal, Carnatic Shoal

Chart 93046 – approx. 8–10°N, 115–117°E;^[6] Sailing Directions pp11–12.^[1]

• 1.30 & 1.31 Eastern SE
  • Half Moon Shoal, Bombay Reef, Royal Captain Shoal
• 1.32 Central SE
  • Sabina Shoal, Boxall Reef, Second Thomas Shoal
• 1.33 & 1.34 Western SE
  • Mischief Reef, First Thomas Shoal, Alicia Annie Reef

Chart 93047 – approx. 8–10°N, 113–115°E;^[7] Sailing Directions pp12–13.^[1]

• 1.34 & 1.35 Union Bank
  • Johnson Reef, Collins Reef, Sin Cowe Island, Whitsun Reef, Grierson Reef, Lansdowne Reef,
• 1.36 Central SW
  • Bittern Reef, Allison Reef, Cornwallis South Reef
• 1.37
  • Pearson Reef, Pigeon Reef, Commodore Reef
• 1.38
  • Investigator Shoal, Ardasier Reef, Ardasier Bank
• 1.39
  • Erica Reef, Mariveles Reef, Dallas Reef, Barque Canada Reef.

Sailing Directions pp13–15.^[1] Other parts of the Spratly Islands which are not inside Dangerous Ground include:

• 1.41 – 1.43 West of Dangerous Ground
  • Fiery Cross Reef, London Reefs, Spratly Island
• 1.44 – 1.48 South West and South of Dangerous Ground
  • Amboyna Cay, Southwest Bank, Rifleman Bank, Swallow Reef

The sovereignty of many of the islands is disputed, as are economic claims.

• C.S. Hutchison, V.R. Vijayan, "What are the Spratly Islands?" Journal of Asian Earth Sciences 39:371–385, 2010 PDF
• David Hancox, Victor Prescott, "A Geographical Description of the Spratly Islands and an Account of Hydrographic Surveys Amongst Those Islands", Maritime Briefing (University of Durham) 1:6, 1995, ISBN 1-897643-18-7 full text