WWJP74 RJTD 161200 IMPORTANT WARNING FOR OTARU NAVTEX AREA 161200UTC ISSUED AT 161500UTC WARNING(DENSE FOG) SEA WEST OF SAKHALIN, SOYA KAIKYO, SEA WEST OF HOKKAIDO, SEA OFF SOUTHERN COAST OF MARITIME PROVINCE POOR VIS 0.3 MILES OR LESS IN PLACES NXT WARNING WILL BE ISSUED BEFORE 162100UTC =