A spoken version of the comic book with the same name (‘the iron haddock’). Suske en Wiske (Dutch) is Spike and Suzy in England, a strip that ran from 1945 onwards. The story itself was first published in 1955 and appeared in a newspaper. This record is from 1987.
In the story Spike and Suzy are trying to win a race to some pearls, deep under the sea. They do that in a so called bathyscaphe. I had no idea what that is. Hurray for wikipedia. It turns out to be a deep sea submarine, that is more than a normal submarine built to resist the extreme high pressure of the deep sea.
It so happened the first one of these was built in Belgium, in 1954. A second version of the ship was used to go around 11 km deep in the Mariana Trench in 1960. It was a record that was kept until 2019. So this revolutionary invention got some extra attention in this album.