This measure has been suggested following the unprecedented incident of scores of devotees being bitten by stingray and jellyfish at Girgaum Chowpatty Beach during the first phase of Ganesh idol immersions on Tuesday.
Around five dozen devotees who had stepped into the sea waters suffered sharp bites by these fish and rushed out crying, feeling giddy and complaining of nausea.
The civic authorities' investigation showed hordes of stingray and jellyfish which had come to the shores in the shallow waters had targeted the devotees.
Chief Minister Prithviraj Chavan on Wednesday directed the civic authorities to initiate measures to counter the underwater menace.
Civic officials discussed the issue in the evening and came up with several measures to save the devotees from fish-bites in the next phase of Ganesh idol immersions.
The BMC advised that devotees should not step into the sea bare bodied, wear gumboots and use the special rafts and boats to carry the idols into the water.
It also advised the devotees not to allow children to enter the fish-infested waters.
The BMC plans to increase the number of rafts and boats for the immersions and set up medical centres at the various immersion spots to handle fish-bite emergencies.
The 10-day Ganeshotsav, Maharashtra's biggest public festival, started here on Monday with an estimated 200,000 gigantic, big and small idols brought for worship in public pandals and homes.
Around 20 percent of these were immersed during the first phase on Tuesday and more will be taken for immersion during the next phase on the fifth day, seventh day and the grand finale, the 10th day.