The Sea Lanes — SLOC, Maritime Theaters, Freedom of Navigation
How sea lines of communication are mapped, defended, and contested — and why a passing warship matters
On September 30, 2018, the U.S. Navy guided-missile destroyer USS Decatur transited within 12 nautical miles of Gaven Reef and Johnson Reef in the Spratly Islands — features in the South China Sea that the People's Republic of China claims as territorial waters and that the U.
S. State Department, citing the United Nations Convention on the Law of the Sea, regards as either rocks or low-tide elevations not entitled to a 12-nautical-mile territorial sea. During the transit, the Chinese Navy destroyer Lanzhou crossed Decatur's bow at a closing distance reported by the U.
S. Navy at approximately 41 meters — close enough that Decatur's commander had to alter course to avoid collision. The Decatur's transit was a routine Freedom of Navigation Operation; the Lanzhou's response was, by all accounts, the closest unsafe encounter between U.
S. and Chinese warships in years. Nothing was destroyed.
That is the opening. Finishing a lesson is where it stops being interesting and starts being useful: the full lesson runs to 7 sections and ends with 6 practice questions. A free account is what opens the rest, and the other 255 lessons in the Academy with it. No card.
What this lesson covers
- 1Eight major maritime theaters that organize global naval analysis
- 2Freedom of navigation operations — what they are and what they are not
- 3The UNCLOS framework — sovereignty zones and the navigation rights inside each
- 4UNCLOS zones at a glance — what coastal states control, what foreign vessels can do
- 5USS Decatur and PLAN Lanzhou — Gaven Reef, September 30, 2018
- 6Where to see this on the platform
- 7Summary