Well, the CG release doesn’t say that specifically do they? They specify in reduced visibility conditions—which suggests a subjective judgmental consideration based on weather conditions. As for radio, I recall a previous thread on the relationship of COLREGS to radio. Is it really a violation when COLREGS doesn’t mention radio? But here again, unless there has been an official communique to the Russian Federation, has the CG made a judgment of violation as opposed to concern on what has been a routine event annually?