Vladivostok whole year open for warships including submarines according to the Dutch magazine Marineblad dated 1937 no. 4

An item referred to the magazine R.M. dated May 1937 reporting that a floating dry dock with as dimensions 129 x 31 metres was towed from Odessa, Ukraine, Russia towards Vladivostok. Thanks to the use of icebreakers was the harbour of Vladivostok the whole year accessible for all ships including submarines.