The Historie van de Oceanografie Club (HOC) is a Dutch initiative with an international reach, bringing together individuals with a shared interest in the history of oceanography. Founded in 2005, the club serves as a network that promotes the exchange of knowledge, access to historical sources, and the initiation of research and meetings in the field. As part of its activities, HOC publishes the newsletter ad HOC, usually once a year. The newsletter serves as a platform for sharing news, research contributions, event reports, and other information relevant to members and others active in the field. The most recent issue (ad HOC, no. 23, May 2026) includes, among other contributions, the article by Samuel Gutestrand Mandarić, “Bornö Marine Research Station and the Emergence of Swedish Hydrography”, found on pages 30–36.