This article introduces all aspects of the global ocean forecast applications, which is very comprehensive and detailed.

1. Firstly, the overall structure of the article could be classified according to application scenarios rather than regions. Examples can be given to illustrate what applications there are in those regions.
2. In 2 The West Pacific and Marginal Seas of South and East Asia and 3 Indian Seas, there are also applications like storm surge, climate change, ship routing, water quality, Coastal tourism, Coastal Engineering and so on. Moreover, there’s no detailed operational forecasting systems and its applications in China, which is suggested to be included in.
3. Both titles 2.4 and 2.5 refer to natural resources and energy. They should be merged.
4. In 6 North-East Atlantic section, titles 6.1 to 6.5 have the word “sector”, but there are no “sector”in other parts. Please keep the consistence in the whole article.
5. The Format of 8 North America is different with other sections. There are no subset serial numberin 8.

This paper gives an example-based overview of downstream applications of ocean forecasting systems around the world, broken down into eight regions dealt with in turn. It is successful in conveying a sense of the range of applications that exist, with many interesting examples provided. Where I feel it misses an opportunity though, is collating that information into a coherent summary of the global status of ocean forecasting applications.

General comments:

The paper would benefit greatly from a summary section at the end that discusses, in the context of the regional overviews and examples provided, the overall status of ocean forecasting applications globally. What commonalities are there between regions? Where do regions differ? Which applications are well served? Which are not being addressed as well as they should? What lessons can be learned from the examples provided? Where are the major gaps?

The methodology could be better described. This could either be done by expanding the end of the Introduction section, or by adding a short new section following the introduction. Things I’d like to see clarified include:

• How were the examples chosen? From some kind of survey or search? Through the DCC Regional Teams? Just through the authors’ personal knowledge?
• Most of the focus seems to be on use of large public sector forecasting systems. Is this an accurate reflection of the state of ocean forecasting applications, or a result of smaller-scale entities and applications not having visibility on the international stage? I don’t know the answer, but if the authors have any insights these would be worth noting.
• The subsection headings (e.g. Oil Spill, Marine Litter), have some commonality between regions, but aren’t consistent. Please clarify whether there was an attempt to categorise examples under certain headings for each region (in which case the absence of it for a region could be taken to imply there are no mature examples), or if for each region a subset of examples was chosen independently.

The initial overview for each region could helpfully be expanded in a lot of cases. The African Seas overview gives a good concise summary of the general status of ocean forecasting applications around Africa. In contrast, the Indian Seas overview is rather generic. In all cases though, I’d encourage the authors to review these overview sections to ensure they meaningfully summarise the specific situation in each region, while minimising generic statements that could apply to all or most regions.

There is an inconsistency in the length of the different sections. For instance, the Indian Seas section is less than a page, whereas the North America section takes up 11 pages (a third of the manuscript) despite largely focussing on a single country. Some discrepancy in section length is reasonable, but this feels excessive, and the authors should ensure a fair amount of focus is given to each region. The balance between comprehensiveness and conciseness isn’t always as well achieved as it could be. Some sections need expanding on, others need tightening up to avoid the paper being excessively long.

One option could be to include, as part of a new section following the Introduction, an overview of common applications (e.g. oil spill, ship routing, search and rescue, etc) which deals with generic (non-region-specific) aspects. The specific regional examples in the following sections could then be streamlined, which may aid with ensuring the manuscript works as a clear coherent whole.

The manuscript is mostly well written, but I’d recommend a thorough read through the entire manuscript to check both for typos/grammar and tightness of language (e.g. L42: “both … as well as”).

Specific comments:

L32: “Also emphasized is the important role of ocean literacy and citizen science to increase awareness and education in these critical topics”. Ocean literacy and citizen science receive only limited mention in the manuscript. Given it’s highlighted in the abstract, it would be good to bring this out a bit more in the text.

L34: “with emphasis given on their level of maturity.” This is a good aim, but hasn’t been achieved as well as it could be. I suggest a review of each section’s text with this aim in mind.

L54: “eight of the nine regions.” To help this be read as a standalone paper, please specify with a reference the context in which these regions were defined.

L57: “The OceanPrediction DCC Atlas of Services, a web portal that will be launched soon.” I believe this is already launched (https://www.unoceanprediction.org/en/atlas) though remains a work in progress. The text could be updated to reflect its status.

L61-63: “in several countries including Australia, China, Japan, and Korea in 2000s and Indonesia in 2010s. There are no significant endogenous research and development activities targeting operational forecast systems in other countries.” From a language point-of-view, “in several … including” implies the list of countries is non-exhaustive, but the next sentence implies it is exhaustive. Also, while it may not be on the scale of efforts in the countries listed, activities in New Zealand (https://www.metocean.co.nz/, https://www.moanaproject.org/) may merit mention. Furthermore, “no significant endogenous” implies that there might be significant exogenous examples in other countries – is this the case?

Section title 2.5 Natural resources & energy repeats that of Section 2.4, and I suspect should be something different.

L137: “'Boast Safety Index' (BSI)”. Should “Boast” be “Boat”?

L215-216: “In South Africa and Mozambique the met services and a local municipality have developed downscaled storm surge models (Section 3.1.4).” There is no Section 3.1.4, and there is no apparent extant section in this manuscript this might be referring to.

Section 8 subsections lack numbering.

L571-575: This is a good example of generic information about an application type which could be dealt with in an overview section.

L578-611: The description of NOAA and other US agencies’ role in oil spill response is genuinely interesting, but an excessive level of detail for this particular paper. It is also in danger at times of reading like an advert for NOAA (e.g. “NOAA brings scientific expertise to the table to help answer these questions.” – which an internet search tells me is taken directly from https://oceanservice.noaa.gov/hazards/spills/).

L627-636: This text appears to be copy/pasted verbatim from https://www.sarsat.noaa.gov/about-sarsat/, now-broken hyperlinks included.

The above three comments could be applied to much of the North America section, which I suggest is revised accordingly. At the moment it mostly appears to be a collection of text taken from various NOAA websites, rather than a truly representative overview of the continent’s ocean forecasting applications.

Table 1: On the one hand, using a table like this can neatly summarise a large amount of diverse information, and part of me thinks the technique should be used more widely in the article. On the other hand, Table 1 is more a list of systems than applications (the latter being the focus of the paper), more than a dozen of which are run by a single agency. On balance, I suggest removing Table 1 and incorporating the most pertinent information and references from it into the revised North America text.

L804-805: “As detailed in Section 3.1.9, there are a number of short-term (up to 10 day) forecasting systems available in the Arctic.” Another reference to a non-existent section and information that doesn’t seem to exist in the manuscript.

L817: “NWS” – presumably National Weather Service, but worth expanding and clarifying that it and NOAA are US agencies.

9.2 Fisheries: This is an interesting paragraph, but it is unclear whether there are any existing applications (known to the authors) or just an emerging need. This should be clarified. Similarly, for Section 9.4.