Angelo Secchi, an influential Italian astronomer, is renowned for his contributions to both astronomy and oceanography. In a notable demonstration, he employed the Secchi disk aboard Pope Pius IX's yacht, L'Immaculata Concezion. This device, consisting of a circular disk that is lowered into the water, measures water clarity based on the depth at which it disappears from view. Secchi's method was straightforward yet revolutionary, marking a significant advancement in monitoring water quality and aquatic ecosystems. The use of the disk connected scientific measurements with observations crucial for understanding the health of marine environments.

During this event, Secchi highlighted the growing interest in the scientific study of the sea, and his work captured the attention of Europe’s educated elite. Secchi's demonstration was not merely a scientific pursuit; it was also a spectacle of curiosity, showcasing the blending of intellectual inquiry and the leisure of the aristocracy. The Pope's patronage served to amplify Secchi's work, linking religion, politics, and science in a period characterized by rapid advancements in various fields. This intersection was significant in propagating scientific knowledge among non-scientific audiences.

The utilization of the Secchi disk marked the beginning of systematic studies of aquatic light penetration and transparency, laying the groundwork for future research in limnology and oceanography. Secchi's methods influenced the way scientists approached the study of water quality, initiating a trend that emphasized quantitative measures in environmental science. This demonstration aboard the papal yacht highlighted the natural curiosity of the time and showcased how scientific methodology could be applied outside of conventional laboratories.