After the tanker had left the loading jetty, she saw the frigate coming down the fjord on her radar, but had no way of knowing which ship it was, because the frigate's AIS was switched off the officer of the watch called the VTS to ask, but the VTS similarly had no idea. The tanker then hailed 'the unknown ship' by radio to ask her intentions, but had no response. A few minutes later, the tanker anxiously called the VTS again, who then said that it was possible that the unknown vessel was the frigate, but had no info on her. The tanker then called the frigate by name, and got a response, but little sensible reaction from them.