Royal Netherlands Navy officers did indeed see an "interesting and ingeniously constructed mechanism in the vessel,"[This quote needs a citation] but were hesitant about their practicality.

[1] During World War I and the interwar period, the Royal Netherlands Navy ordered and built many submarines.

Due to the economic malaise and the high costs caused by operations in the Dutch East Indies, there was no money left for new construction.

In 1946, the Netherlands still had a total of eight operational submarines in service: HNLMS O 21, O 23, O 24, O 27, Dolfijn, Zwaardvisch, Zeehond, and Tijgerhaai.

[5] Since the home port at Den Helder was in ruins, these submarines were for the time being using the Waalhaven in Rotterdam as their base.

Since the Dutch submarines were ideally suited for unnoticed explorations, the OZD was mostly focused on gathering intelligence during the Cold War.

[citation needed] In the period from 1970 to the 1990s, the crew of the six Dutch submarines secretly gathered information about the Soviet Union.