A global compilation of in situ data is useful to evaluate the quality of ocean-colour satellite data records. Here, we describe the data compiled for the validation of ocean-colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI). The data were acquired from 40 sources (including, inter alia, MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT, GeP&CO and BIOCHEM) between 1996 and 2025. Observations of the following variables were compiled: spectral remote-sensing reflectance, chlorophyll-a concentration, spectral inherent optical properties, spectral diffuse attenuation coefficient and total suspended matter. The data were obtained from multi-project archives acquired via open internet services, or from individual projects acquired directly from data providers. Methodologies were implemented for homogenisation, quality control and merging of all data. Minimal changes were made to the original data, other than averaging observations that were close in time and space, elimination of some points after quality control, conversion to a standard format, and application of a bidirectional reflectance distribution function (BRDF) correction to remote-sensing reflectance data. The dataset compilation consists of several files in CSV format, and rows in those files relate to each other via the unique key (column idx). Metadata of each in situ measurement (original source, cruise or experiment, principal investigator) were propagated throughout the work, enabling processing of individual datasets separately, if needed. Compared with the previous version (Valente et al., 2022), this release incorporates updates from nine existing data sources and includes data from thirteen additional sources, increasing the total number of observations from 148,432 to 319,183 and extending the temporal coverage from 2021 to 2025. This paper also describes the changes that were made to the compilation in relation to the previous version.