Where in the World is Theunis Ariens van der Giesen?

Arie Jansz. van der Giessen and Ariaantje Ariens Buijtendijk were married on 30 May 1717 in Westmaas, Holland. They became the parents of a large family of 11, including a son Theunis, baptized on 24 September 1719 in Numansdorp, Holland.

Theunis Ariensz. van der Giessen, originating in Numansdorp, joined the Dutch East Inda Company (V.O.C.) as a soldier, protecting ships. On 29 March 1741 Theunis sailed from Goeree, an island in the southwestern part of Holland, on a flute ship named “Delfland”. Its skipper was named Egbert Verduin. Its crew consisted of 119 sailors and 60 soldiers, including Theunis. 
A long-distance voyage was hard on the health of a sailing ship’s crew. During the first 2-3 months of the voyage newcomers aboard usually developed scurvy due to a vitamin C deficiency. The “Delfland” arrived at Cape of Good Hope in South-Africa on 24 June, departing at 18 July. Ship and crew arrived on 11 September 1741 in Batavia, the capital of the Dutch East Indies, corresponding to the present-day city of Jakarta.
After staying in Indonesia for over year, Theunis Ariensz van der Giessen was supposed to board ship for the homeward voyage on 20 November 1742, but he never turned up. He has been missing ever since.

Salary and expenses of Theunis Ariensz. van der Giessen

Sources: V.O.C. opvarenden bij het nationaal archief, huygens.knaw, VOCsite.nl. 

You can read about Theunis van der Giessen in the Dutch language, too:

Theunis Ariensz. van der Giessen uit Numansdorp bleef in Azië