As Hong Kong's intrepid protesters sail with their hearts in their mouths towards the Diaoyu Islands on the creaking Kien Hwa No 2, they can be assured of one thing: the coastguard will not leave them to drown. 'Our mission is rescue,' said a spokesman for the Maritime Safety Agency, the Japanese ministry in charge of the Diaoyu blockade and the coastguard service. If the boat sank, or a landing party got into trouble while trying to push past the offshore defences they would be helped. But there was no assurance anyone who did make it to the shore would not be arrested or even shot. 'I can't say what we would do. It's a secret,' the spokesman insisted, although he admitted there had been discussions between the agency, Japanese police, Customs and immigration authorities and the Foreign Ministry. At this stage, it was only possible to say boats approaching from outside Japanese waters would be warned and escorted out again. If they persisted in trying to sail for the shore, they would be given another warning. Beyond that, all operational plans were secret. Despite the inter-agency co-ordination, all vessels involved in the operation were coastguard craft, relatively lightly armed with 35mm guns only.