The Straits of Malacca
are one of the great shipping lanes in the world. It is a narrow strip of water between the Malay Peninsula and the island of Sumatra and it is the superhighway for shipping between the Pacific and the Indian Oceans. Near Singapore the shipping lane narrows to only about a mile and a half in width and is a very congested choke point.
Almost 100,000 ships pass through the Straits of Malacca each year and they carry a quarter of the worlds bulk goods and oil. There is a limit to the size of vessels that can pass through the straits as the maximum depth is 82 feet - this restriction in naval architecture is known as Malaccamax. Ships that exceed this must take the Lombok Strait between Bali and Lombok or other routes that can add thousands of miles to their route.
With so much traffic flowing throw Malacca, piracy has always been an issue and there have been naval battles there in both World Wars.