The abundance of tankers available for charter has dramatically cut rates, making it more important for independent shipping companies to keep costs down to squeeze a profit out of each voyage.

With shipments scheduled well in advance, delays on one trip can mean missing an appointment to pick up another load for the next voyage and losing the charter.

For refineries, late deliveries can mean no oil for processing, causing expensive shutdowns and restarts.

The Malacca Straits near Singapore has long been a popular short-cut between Europe and Asia. With its increased importance as a link between Japan and the Middle East oil fields, the straits have become even more popular and congested.

About 200 large merchant ships and 1,800 smaller vessels, including fishing craft, choke the 965-kilometre waterway each day.

Malaysia wants to charge ships using the straits a toll, but the shipping community has objected on grounds that every country bordering a popular passageway might do the same.

In January, the supertanker Maersk Navigator, carrying nearly 360 million litres of crude oil, collided with an empty tanker near the entrance to the straits.

Last November, the tanker Nagasaki Spirit collided with a container ship, spilling about four million litres of petroleum.

The straits also have seen recent collisions between a fishing trawler and a cruise ship, and between a United States Navy destroyer and a cargo ship.

Piracy has increased sharply in the straits. Last year, 73 pirate attacks were reported in Southeast Asia, about half of them at the opening to the straits where ships slow before moving into the channel.

Avoiding the pirates and congestion of the Malacca Straits would mean sailing about 3,200 kilometres to the southeast to the Indonesian island of Lombok and passing Indonesia and the Philippines to the east, rather than the shorter western route.

Slow-moving, low-riding and thinly-staffed oil tankers are susceptible to pirate attack but no boardings have resulted in spills.

Pirates usually pillage the crew's quarters.

Ideas suggested by insurers to discourage short-cuts include charging shipping companies higher premiums when they risk safety to save time or providing insurance against lost profits if decisions are made in favour of safety.

But shipping experts say the industry's focus on spill prevention continues to centre on poorly trained crews and old vessels.

And pressure is building in the industry to prevent rust buckets from sailing. More people are calling on oil companies, port officials and maritime safety experts to share survey data on an international database.

Currently, such information obtained by flag states, insurers, port authorities or charterers is kept themselves and not passed on.