The collection of high-accuracy and robust bathymetric data is of paramount interest for any hydraulic and coastal study. Moreover, because of the complex morphology of river deltas, the bathymetry collection and interpolation are challenging. The paper presents well the analysis of different datasets and their interpolation in the river branches of the Danube Delta. The paper is well written and well structured, and results are clearly presented, with relevant figures and tables. I compliment the authors for their data collection and analysis work. 

I recommend publication, subject to the authors addressing the comments made below. I strongly recommend focusing abstract, section Application (4.4) and Conclusions on the topic of this dataset without digressing on future work on land-sea (modelling) studies (which can be the subject of another paper). Moreover, I suggest the author mention that such a dataset could be further improved including the bathymetry of the coastal area in front of the delta.

The study presents a well-structured and methodologically rigorous approach to high-resolution bathymetric modeling of the Danube Delta, effectively integrating multiple datasets and employing an adaptive interpolation framework to capture the complex morphology of the river system. The scientific methodology is sound, particularly in the use of a curvilinear, non-structured coordinate system combined with an anisotropic Inverse Distance Weighting (IDW) interpolation method, which enhances the spatial accuracy of the final dataset. Despite the inherent limitation of integrating multiple bathymetric databases, the authors adopt a sufficiently rigorous technical and scientific approach to ensure a consistent and methodologically robust expansion of the dataset over such an extensive and complex study area. 

In my opinion, one of the primary limitations of the study lies in the relatively low resolution of the topographic data extracted from the Copernicus DEM (30m resolution). This may introduce uncertainties in the precise delineation of the shoreline and the transition between land and water. Given the importance of accurate topographic information for hydrodynamic and flood modeling applications, the use of a higher-resolution DEM could significantly enhance the reliability of the dataset. If such high-resolution topographic models are not available for this region, it would be beneficial for the authors to explicitly acknowledge this limitation in the text, clarifying whether finer-scale topographic data were considered but deemed unavailable or providing a justification for the choice of the Copernicus dataset. 

Another key issue arises from the temporal mismatch between bathymetric and topographic data sources. River deltas are highly dynamic environments subject to morphological changes due to sediment deposition, erosion, and anthropogenic interventions, which may not be fully captured in the compiled dataset. The use of more temporally consistent datasets could improve the accuracy of hydrodynamic modeling. If no such datasets are available, the authors should explicitly state this limitation, specifying whether efforts were made to identify topographic data closer in time to the bathymetric surveys and explaining the rationale behind the chosen dataset. 

In terms of readability, the paper is generally accessible, though some sections—particularly those describing interpolation techniques and coordinate transformations—could benefit from greater clarity and conciseness. While the technical language is appropriate, in some instances, overly complex phrasing may hinder comprehension for non-specialist readers. The use of English is strong overall, with only minor grammatical or stylistic issues that do not significantly affect readability. 

The figures and illustrations are well-designed and effectively support the text, providing valuable visual representations of the dataset, methodology, and results. However, some maps and graphs could benefit from higher contrast or improved labeling to enhance readability and interpretation. 

Given the relevance and potential applications of this dataset, the authors could consider including, as a prospective future development, the dissemination of their dataset through WebGIS platforms. This could be explicitly discussed in the Discussion or Conclusions section as a logical extension of their work. Implementing a WebGIS service would allow users to visualize, query, and analyze the dataset interactively, thereby significantly improving its accessibility and usability. Such an approach would expand the dataset’s reach beyond the scientific community, making it a valuable resource for policymakers, environmental managers, and other stakeholders engaged in hydrodynamic modeling, flood risk assessment, and coastal zone management in the Danube Delta. By facilitating broader access and integration into decision-making processes, such an initiative would maximize the dataset’s impact and further support interdisciplinary environmental assessments and planning efforts.