What is prefered timing for passage from Japan to Kuriles to Petropavlovsk to Aleutians to Kodiak?? Do you have visa data for Siberia ??

Summer is the best time to attempt a passage NE from Japan (June to late July or early August). You need to allow time for the onward voyage, so the window is quite narrow.

You need a visa for Russia obtainable from a Russian embassy.

Jimmy Cornell