This dataset contains supporting data and reproducible analysis material for a carbon-flow food-web modelling study of the hydrothermal vent field Penumbra site 10 on the South East Indian Ridge. The underlying image material was collected during the INDEX 2023 expedition with RV Sonne and the remotely operated vehicle ROPOS. The data were used to build four carbon-based linear inverse food-web models representing three distance areas around active chimneys, 0-5 m, 5-10 m and >10 m, and one integrated total-site model.The dataset includes a biological annotation workbook with event metadata, parameter descriptions and megafaunal abundance data, associated annotation image material, taxon-specific biomass measurement files generated with ImageJ and the ObjectJ plugin, biomass summary tables, linear inverse model input files, conversion and parameter tables, model output files, diagnostic plots, run logs and R scripts. The R scripts document the workflow used for data merging, model sampling, convergence analysis, trophic-level calculation, network-index calculation and omnivory-index analysis.Megafaunal abundance information was derived from remotely operated vehicle image annotations. Biomass estimates were based on image-based biovolume measurements and taxon-specific conversion factors. The model input files combine these imagery-derived standing stock estimates with literature-based physiological and trophic constraints.