The manuscript provides a contribution to modelling the impact of seagrass on waves by integration of seagrass flexibility and seasonality in a numerical model. I think the presented work is a valuable advancement of numerical modelling of the impact of seagrass on wave attenuation, highlighting the impact of variation. Unfortunately, I found several aspects not described very clearly in the manusript and hence encourage the authors to revise the manuscript for clarity and precision in the wording. I have made specific comments in the attached document. I recommend to place a particluar focus on the conclusions section, which is more a repeat and summary as it stands.

The manuscript by Shirinov et al. can contribute to advancing the modelling of wave propagation over seagrass beds in field conditions by including the influence of seagrass flexibility and seasonality in a widely employed numerical framework. All the relevant aspects of the work have been described on the manuscript, including field data of seagrass biomechanical properties and model validation. However, there are quite a few issues that should be tackled by authors with a thorough revision. My major concerns are:

• The equations employed to describe seagrass bending in response to the flow are valid for unidirectional flows. If this is not a typo, the simulations should be repeated implementing the right set of equations developed for oscillatory flows.
• To assess the impact of flexibility, I would expect that a comparison between the case of rigid seagrass and that of flexible seagrass is performed. The present comparison between non-vegetated bed and beds with flexible seagrass is inherently influenced by the presence of the seagrass regardless of its mechanical properties. How can the influence of flexibility be isolated with the results presented?
• The wave attenuation predicted by the model is compared across the four Sites of Community Importance and three different substrates. However, the discussion does not critically assess why the impact of flexible seagrass is different across sites/substrates based on the phenotypic traits of the plants available from the sampling campaign. I suggest the authors to work on this aspect to strengthen the manuscript by linking better the outcomes of their model with the (expected) underlying physical mechanisms.
• Conclusions are rather weak and should be re-written.

More specific comments, and comments related to the presentation quality, are included in the attached document.