1935 envelope to Groningen, Holland with a blue Type V cancel and a Dutch Submarine Cachet “Met Hr.Ms.K XVIII / Vervoerd van Tristan da Cunha / Naar Kaapstad”. A Cape Town 2 APR 35 Paquebot cancel is on the front of the cover. On the back is an endorsement by Submarine Officer C v/d Linden with ‘Tristan Da Cunha’ written underneath. The Dutch submarine K XVIII visited several harbours: Den Helder, Funchal (Madeira), St Vincent, Dakar, Pernambuco, Rio de Janeiro, Montevideo, Buenos Aires, Mar del Plata, Tristan da Cunha, Cape Town, Durban, Mauritius, Fremantle and Soerabaja. The submarine arrived at Cape Town on April 1, 1935. Less than 12 covers with this cache tare known from Tristan Da Cunha. Sismondo 2016 certificate.