NEW DELHI: Navy chief Admiral Karambir Singh has asked his force to guard against outbreaks of the deadly coronavirus on board warships and submarines while continuing to maintain full operational readiness, in the backdrop of the highly contagious Covid-19 hitting operations of four US and one French nuclear-powered aircraft carriers around the globe.“We have to ensure our operational assets, warships and submarines, remain free from the virus…I know it’s a very difficult task because physical distancing on board warships, especially submarines, is a great challenge,” said Admiral Singh, in a video message to the rank and file of the 140-warship and 235-aircraft maritime force on Thursday.The Navy has to ensure combat readiness across the entire spectrum, from keeping a hawk-eye on the Indian Ocean Region to dealing with asymmetric threats, while continuing to play a crucial role in helping the country as well as maritime neighbours in combating the pandemic.“We (armed forces) really are the last bastion in this national effort against the pandemic…The danger is real, imminent and unprecedented...Care-givers cannot become care-seekers,” said Admiral Singh.The Navy chief’s message comes soon after four American 100,000-tonne aircraft carriers, USS Theodore Roosevelt, USS Ronald Reagan, USS Carl Vinson and USS Nimitz, as well as the French Navy's flagship Charles de Gaulle reported Covid-19 cases.The case of USS Theodore Roosevelt, in particular, created shock waves in military circles last week after it was forced to dock at Guam to evacuate most of its around 5,000 sailors, leaving only a skeletal crew on board to maintain its nuclear reactor and other critical operations.The skipper, Captain Brett Crozier , who himself has tested Covid-19 positive now, was relieved of command after his letter criticizing the Pentagon’s handling of the outbreak on board the mammoth warship became public.“We are not at war…sailors do not need to die,” he wrote. The controversy also led to acting US Navy secretary Thomas Modly’s resignation for mishandling the situation and mocking Capt Crozier.Indian armed forces have so far not been hit by Covid-19 in a major way, except for some cases here and there. Indian warships deployed in international waters are avoiding port calls since last month, while also following strict protocols to ensure Covid-19 does not make any inroads, as was reported by TOI earlier.Admiral Singh, on his part, said his force has to be prepared for the “worst-case scenario” in the days ahead. The measures needed could range from helping cross-state movement of goods and essential supplies through the sea and air routes to creating “alternate areas for mass isolation and quarantine” and assisting management of law and order, he said.