Besides the police, the Indian Navy has positioned relief teams at the sea fronts in Malad, Ghatkopar, Mankhurd, Worli and Colaba. It has also provided two teams of Naval divers at Chowpatty and Powai with the latest equipment.

Similarly, the Coast Guard has deployed a high speed vessel, an interceptor boat and one helicopter off Mumbai to ward off any potential security threat during the immersion.

By late Thursday, an estimated five million people are expected to join the immersion ceremonies across the city and suburbs. The day is a holiday in Maharashtra.

The MCGM has deployed 40,000 staffers to oversee the immersion arrangements, 56 motorboats at various locations, 500 lifeguards, and 6,000 volunteers. It has also set up 60 first aid centres, 52 ambulances, 12 mobile toilet complexes and 31 watch-towers at the sea fronts.

'From the 10,000-plus public associations (sarvajanik mandals), the idols range from the tallest - a 28-foot high idol of Lord Ganesh, installed in Ganesh Gully, Lalbaug in central Mumbai -- to the tiniest - a mere three-foot tall idol installed by the Vikas Sarvajanik Ganeshotsav Mandal at Bhandup in northeast Mumbai,' Brihan-Mumbai Sarvajanik Ganeshotsav Samanvay Samiti vice-president N. Dahibhavkar told IANS.

This year, there are 120 large Ganesh idols in different parts of Mumbai, a decline of around 20 percent over last year on account of security reasons, the swine-flu and recession, he said.