Light is an important parameter for the marine ecosystem with numerous functions. The Pacific represents a large portion of the Earth's water masses and marine ecosystems. Although the Pacific Ocean has been extensively studied, little is known about its remote areas. The aim of the OceanLight project was to determine the above and underwater light field hyperspectrally on a transect through the Pacific (from Fiji to Mexico). These measurements extend data gained from previous expeditions with RV SONNE in the Pacific, where hyperspectral underwater light field measurements were carried out on SO245, SO248 and SO254. Thus, most of the major biogeographical provinces of the Pacific are covered. Public available hyperspectral in situ data also supports satellite remote sensing with reference measurements.

A second topic of the project focused on the validation of the newly installed "Underway" measurement system on board RV SONNE. This transit offers the first possibility for the home institute of the research vessel to validate the flow-through system, which is equipped with hydrographic and optical sensors, extensively with reference sensors and sampling. The OceanLight project was one of three projects that were conducted on the SO267 / 2 transit.