The heavy maritime traffic involving massive cargo ships in what is considered the country's busiest port and the presence of smaller vessels like fishing boats, tourist boats, sand dredgers, barges and private luxury yachts, besides defence ships, in the area have made the Mumbai harbour and its surroundings a sitting duck for shipping disasters.
Top officials from the Indian Coast Guard (ICG) and Directorate-General of Shipping (DGS) said high traffic apart, there is also human error involved in the maritime accidents in and around the Mumbai coast.
"It cannot be said that the frequency of accidents has increased or decreased in the past couple of years. However, the visibility of accidents in recent times has gone up," Director General S.B. Agnihotri told IANS.
Explaining 'human errors', Agnihotri said accidents happen even though each vessel - entering or leaving the Mumbai harbour - is given a pilot to guide it in or out safely.
According to S.P.S. Basra, inspector-general (West), ICG, there have been eight big and small incidents of ships being grounded in 2011, seven in 2010 and six in 2009.
In an incident March 23, 2010, an Indian Coast Guard ship (ICGS) was rammed by a merchant navy ship, M.V. Global Purity, when the latter was being brought for docking at the Mumbai Port Trust.
The merchant vessel hit ICGS Vivek thrice, severely damaging its hull and causing heavy flooding on board when it was undergoing repairs in the Indira Docks. Subsequently, ICGS Vivek sank in the port area.
Barely five months later, on Aug 7, 2010, two foreign cargo ships - M.V. MSC Chitra and M.V. Khalijia-3 - collided in the main navigation channel of the Mumbai harbour, seriously disrupting maritime traffic going in and out of the port, as well as the adjacent Jawaharlal Nehru Port Trust and the Naval Dockyard.
The collision resulted in nearly 400 tonnes of oil spill, some impact of which can still be seen in the mangroves in the Mumbai, Thane and Raigad coastal areas.
Besides the environmental hazards it caused, several huge loaded containers slid and fell off the heavily tilted M.V. MSC Chitra, resulting in the total closure of harbour channel for a fortnight.
A top ICG official preferring anonymity said on account of the high volume of traffic in Mumbai harbour, a lot of traffic has already been diverted to other destinations like the ultra-modern Mundhra port in Gujarat.
"In the next few years, as other ports develop, we hope the congestion and safety situation in Mumbai will considerably improve," the official added.
Another maritime official said as per Indian laws, any vessel which is more than 25 years old is not considered sea-worthy. There must be stringent checks and vessels that do not meet the criteria should not be permitted in Indian waters, he said.
On Aug 31 last year, a coastal cargo vessel, M.V. Nand Hajara, which was docked in Indira Docks for unloading a steel consignment, brushed against another ship, M.V. Beas Dolphin, when the latter was being docked.
One wing ballast water tank of M.V. Nand Hajara sustained a huge hole, leading to ingress of water and tilting the vessel by over seven degrees. Luckily, the authorities got into action immediately and managed to save the ship from sinking.
On Jan 31 this year, the Indian Navy suffered a tragedy when its frontline frigate INS Vindhyagiri collided with a Cyprus-flagged container cargo ship, M.V. Nordlake.
Despite all efforts to save it, INS Vindhyagiri sank the following day, making it the worst-ever peacetime disaster and loss of a precious ship for the Indian Navy.
Two months ago, on June 11, a Singapore-flag ship, M.V. Wisdom, weighing 9,300 tonnes, broke loose from its tugboat, M.V. Seabulk Polver, following inclement weather conditions off the Mumbai coast.
In another incident, a 70-metre long, 1,000-tonne cargo carrier, M.T. Pavit, drifted all the way from Ras-Al-Madrakah near Oman to get stuck in the sands at the Versova beach on July 31.
The latest incident, involving the sinking of the Panama-flagged M.T. Rak Carrier on Aug 4, has raised apprehensions of an ecological hazard once again.
While the Indian defence and maritime authorities Monday said the rate of oil spill has reduced to around one tonne per hour, as compared to 1.5-2 tonnes per hour Sunday, some oil patches have also been sighted as far as 12 nautical miles from the sunken vessel.