I think the paper is interesting and useful for the community. I suggest emphasizing the novelty of this study in the abstract/introduction, since there are similar previous studies. The authos must reorganized some part of the paper, infact some methodological part is present in the results and some discussion is in the results. Probably the authors must check well the units of the reflectances, in particular in the graphs.

Some specific comments:

In lines 39-43: please add some references.

Please check all acronyms in the document; for example, Chlorophyll is written in three different ways.

In line 127: please clarify what “fr” is or, if it is an error, delete it.

In line 293: please replace “sit” with “sites”.

In lines 319-321: I suggest expanding on the section on optical water types. In particular, mentioning the different classes that are then shown in Figure 8.

In line 358: please check the punctuation.

Lines 366-369 "The green (B3) ... (Pahlevan et al., 2021)”, I suggest moving them and expand on them in the discussion.

In section 4 “Research methods”: please add a couple of sentences describing the spectral resampling method that was performed for both in situ datasets. Also add the time window (in terms of hours) that was considered in the study between satellite observations and in situ measurements.

Before Figure 3, a couple of sentences introducing it are missing from the text. Also, check the reference axes, as they appear to be incorrect. “Reflectance”?

For figures 5, and 6, it is not clear what unit is being used on the axes. Please clarify whether you are considering reflectance or Rrs. Make all graphs consistent with each other so that they are easier to interpret. Also, add the wavelengths (nanometers) to the graphs. For example, instead of using B1, I suggest to put 443 nm, and so on.

Lines 404-413: In this section, you discuss the protocols and methods used for the two in situ datasets. This section should be included in the methodology when you explain the datasets used in the work.

Lines 413-414: This section should be included in the discussion. In addition, you could mention not only the uncertainties related to subjectivity in the choice of optical water types, but also briefly refer to some of the concepts mentioned above (404-413). For example, the fact that the AERONET dataset is consistent in its collection of measurements, unlike the GLORIA dataset. This could add more uncertainty to the analysis, and it would be better if you mentioned it in the discussion.

Lines 413-421: This part should be improved. It is a combination of results and discussion.

I suggest adding a brief note at the beginning of the “Discussion” section regarding the results obtained in this work and the uncertainties associated with in situ measurements (as mentioned in points 13-14).

In line 531: Perhaps you are referring to criteria 3-4 and not 2-4. Please check.