In 1926 and 1936 medals were granted by Royal Decree to the National Commission for Surveying (which was instituted on February 20 1879). These medals were to commemorate the trips of 1926 and 1934/35 on Royal Netherland Navy Submarines Hr.Ms. K XIII (1926) and Hr.Ms. K XVIII (1934-35). The K XIII sailed under the command of Luitenant-Commander L.G.L. van der Kun (1892-1962) of Den Helder, via the Panama Canal to Surabaya. The K XVIII was under the command of Lieutenant-Commander D.C.M. Hetterschij (1891-1948) and ran through South America and Cape Town to Surabaya. Along the way observations were done with a pendulum by Felix Vening Meineszlaan who recorded the strength of gravity at sea. On both occasions 35 medals were awarded. Luitenant second class Max Samuel Wytema Officer and Officer Marine Steam Navigation Service C. van der Linden, who had sailed on both trips, recieved two medals.
Obverse: surfaced submarine, surrounded by the text: "Tocht Hr.Ms. KXVIII Den Helder-Soerabaja-14nov 1934-tot 11 juli 1935" (Trip HrMs KXVIII Den Helder-Surabaya-14 november 1934 until 11 july 1935). Reverse: flat with the text "Rijkscommissie voor graadmeting slingerwaarnemingen" (Government Surveying Commission, Pendulum Observations). Diameter: 27mm. Material: Silver, silvermark (sword) on the reverse just below the suspension