The manuscript entitled “Characteristics and coastal effects of a destructive marine storm in the Gulf of Naples (Southern Italy)” deals with an interesting and timely topic. Overall I believe it is an interesting contribution fitting the scope of the journal. The authors use weather-marine data along with modelled data and examine the severity of the December 2020 event in the Gulf of Naples, taking into account local press reports and also discuss the return period of such destructive events.

Overall, the ms is well written and well structured, with high quality illustrations and the conclusions are supported by the data.

I have some minor corrections to propose to the authors, see also the annotated pdf:

• In materials and methods I would propose to add a small paragraph in the beginning introducing the flow chart of figure 2.
• The English needs some refining.

The paper addresses an interesting topic related to the analysis of a marine storm, occurred on the 28th December 2020, the event is analysed through a wind-wave coupled model that takes into account the main weather-marine components of the coastal setup. Model results can support the establishment of threshold values for the management of coastal floods in the investigated zone and for the identification of tailored solutions to reduce the local risk. Nevertheless, in my opinion, before being published, the following revisions can be considered:

• Adding in the “Study area” section some details about the values of the investigated area (e.g. ecological, and/or archaeological, and/or economical value);
• Adding a brief summary of the applied methodology at the beginning of the "Material and methods" section. To this aim, figure 2 can be moved upward in this section;
• Moving Figure 12, 13 and 14 out from the “Conclusion section”. They can be included in “Section 5”

The paper is well written, and the methodological approach is interesting and deserves publication. The author applied a method to investigate coastal effects using the modelling and geological dataset.

I have tried to outline how this might be addressed in the comments below, and hope the authors find this useful in refining the submission.

However, the authors did not consider storm impact studies along the Mediterranean coast in the general description. I suggest introducing this element to understand the global background.

I suggest employing a framework (diagram) to describe the timeline of the processes. This feature could be made more clear your methodology. https://www.sciencedirect.com/science/article/pii/S0964569118303685

In my opinion, a discussion paragraph is necessary. The author should describe the different impacts on the coast and insert some consideration on urban beach management; furthermore, the authors can draw a map that reports the position of the photo (fig. 12 e 13). I think that this improvement could support the manuscript.

The author calculates set-up values in section 3.4; I suggest evaluating the wave run-up to evaluate the inundation level.

Please, introduce the same consideration on global climate change and relative sea-level rise. I think that your manuscript could be more interesting if the authors find a connection between their results and global warming.