Smog warning to shipping

Visibility dropped to half a nautical mile at Tuen Mun yesterday, as a blanket of fog and pollution descended. On a good day, it is 10 nautical miles.

The Observatory blamed water droplets mixing with suspended particulates, which then hung in the air as winds dropped.

Ships were given warnings from 7am as visibility fell below two nautical miles.

By 2pm, it was down to one nautical mile in Victoria Harbour and Kowloon Bay, and half a mile at Tuen Mun, said a Marine Department spokesman.

No warnings were issued to aircraft, said a Civil Aviation Department spokeswoman.

Air pollution hit 102, in the very high range, at Tap Mun Island.