Dear Authors
Thank-you again for your revised manuscript. Both referees have seen it and as a result I am asking for minor modifications prior to publication in Ocean Science.
I am not sure whether you have seen the comments so I am copying them below with a few “editorial” comments from myself. Most are from Referee 1 who is an expert in tides (as well as a “native” English speaker) so please do address these. Referee 2 endorses a couple of points. There is also a comment about figure 9 forwarded via Referee 1 (you might guess where it comes from).

Referee 1
Comments on resubmission of 'Tidal variability in the Hong Kong region'
by Devlin et al. (Ocean Science)
This paper is a resubmission of an earlier and longer paper submitted to OSD which discussed tidal changes in the Hong Kong region, and less convincingly, in the South China Sea. I am pleased that the authors considered my suggestion to shorten it and focus on Hong Kong.
I have read it again carefully and I have no doubt that the analysis has been done well at a technical level. However, my main concern is that the text does not read well at all. I have made some suggestions on rewording below.
The second concern, which I mentioned last time, is that the parameters used (TACs and delta-HATs) are simple ones but they are non-standard in tidal literature (unless you are familiar with Devlin's previous papers). They have to be explained therefore. But the paper assumes that the reader has read, or now wants to read, the previous papers. I insist that the paper have an Appendix wherein these two parameters are explained adequately.
As I mentioned last time, I don't have a problem with the TAC parameter. However, I really don't like the name 'approximate delta-HAT' which goes against all common use of the term 'HAT' in tidal literature. As I understand it, it reflects the maximum level that would be obtained in a year from a chosen set of time-dependent amplitudes and phases extracted by the admittance method. So
please spell this out in the Appendix.

Detailed comments, many trivial to do with the text:
38 .. tidal variability in the 31-year period 1986-2016.
40/41 ... locations, time series of approximations of the parameter delta-HAT, computed from combinations of the major tidal constituents, are found to be highly sensitive ..
44 - individual tides --> individual tidal constituents
49 - as important --> important in combination with
I really don't think tidal changes will ever be as important as MSL rise but as you say the tidal changes will add to the problem
81 - additional shorter-term
82 - and would imply that flood risk
85 - considered as a substantial complement to
89 - critical interest if all such factors are undergoing change.
At this point you should refer to the Appendix.
95 - as a proxy for what can be described as changes ..
99 - was seen
mmm should be mm m
101 - ok so you have tidal changes and MSL in the extremes, what about non-tidal and non-MSL changes like storm surges?
106 - I have never seen the word metropolises used in English (although it is correct I think). I would replace 'urban metropolises' with 'areas'
two extensives in this sentence
109 SCS --> South China Sea (SCS)
You define this acronym only at the moment in figure 2 caption
114-116 - this sentence needs rewording. It reads like you do something by doing the something.
122 - the longest record in Table 1 is 1954-2016 which is 63 and not 65 years
123 - you have not yet explained to the reader that station names are accompanied by station codes, so I would drop (QB) here and see below.
129 environment --> geographical setting
131 .. including station name and station code, latitude .... and the ranges of the data records used in this study.
Then add here:
For brevity, we often refer to stations below by their station codes rather than their full names e.g. QB for Quarry Bay.
You use station codes a lot in the text which seems unnecessary to me when it would be much clearer to the reader to use the place names. There is no space shortage here. So, if you were to remove them all and replace with the names then the above sentence would not be needed.
133-137 - I know what you mean here but this sentence is rather a mouthful. Can you split into two? Also the sentence at line 143 'The tidal potential' should come earlier.
142 - 'effects are eliminated'. Why? I don't understand this. They would be eliminated only in an analysis of 18.6 years and would well and truly still be present in a 1-year analysis.
142 - 'may not always hold true'. You could refer to Amin's papers.
144 start a new para at 'The result'
146 -.. analysis window (e.g. at mid-year) ..
157 - more apparent in the data sets used here
159 - ... MSL variability (Appendix 1). With the use of the TACs we determine ...
164 .. (delta-HAT) (see Appendix 1).
Start a new para.
167 - mmm should be mm m
174 - The use of a window of a year in a harmonic analysis
181-183 This sentence could come earlier where you mention the Appendix
183 start new para at 'For the'
Here you start using codes in the text. I have no idea what TPK means and I can't be bothered referring all the time to Figure 1
30 years should be 31 (1986-2016)
.. determinations (Table 1).
136 .. in the TAC values over time .. [although I am not sure I understand this. I would reword this and simply say that as the TAC could change over time you have adopted a common epoch for the work]
188 twiddle 12-30 --> 12-31 (Table 1).
199 - I was not provided with the supplement
203 - I believe Victoria Harbour is usually spelt with a 'u'. It would be good to show it on Figure 1.
.. all other gauges except .. moderately negative ...
216 - you add the acronyms in the header at line 200 so do the same in the header here
218 discrete --> particular
drop 'In Hong Kong' Five stations ...
229 - HK --> Hong Kong.
233 - drop 'and we report ..'. Irrelevant.
234 - OT --> overtides (OT)
238 drop 'an additional'
241-242 reword: .. Therefore, all MSL values reported here are given relative to the HKPD for the epoch 1965-1985.
246 drop 'drastically'
249 correlated to --> correlated with
254 though --> although
263 - I don't understand the sentence 'The TACs'. What does it mean that they are present? You mean they are large or what? And you don't actually show delta-HATs but you do show the TACs of the approximate delta-HATs. This all needs rewording.
270 The spatial similarity in the ..
284 - with processes at other frequencies, such as at
292 varies with
293 with the spring-neap
294 drop 'away'
307 forcing of the tides
315 - some records are of shorter length and/or have many gaps, making ..
320 as was
328 perform --> employ
three-dimensional numerical ocean models to simulate the changing impacts on
330 comma before 'to better'
As I mentioned last time, one limitation of this study is the possibility of instrumental changes in the tide gauges. You don't even mention what sort of gauges they are or what changes there might have been.
351 drop hyphen in sea level. There should be a hypen only when used as an adjective e.g. sea-level rise.
353 can be positively reinforced by what? by MSL changes?
354 agitate --> aggrevate
360-364 these web addresses should have http or https
368 interest --> interests
383/422 - you could just call it SCS if has been defined in the text
figure 1/2 - add extra names as mentioned above
figure 2 - red on dark blue is not good. I would add China.
Taiwan Strait and Luzon are very small and unreadable when printed in A4
Figure 3 etc. - mention again that red/blue is +/-.
Black marks indicate TACs which are not significantly different from zero.
figure 7 - as I understand it this is not delta-HAT but the TAC computed from the approximate delta-HAt time series made from 4 constituents. Right?
Please reword the caption to make that clear and not read as jargon. Also you have not defined what delta-HAT4 means in the text.
455 sea-level --> sea level
649 giving the station names and station codes, ... year of the available records, as well as the range of data analysed ..
652 - and O1 over the period 1986-2016.
656 - TACs over the period 1986-2016.
337 TAC --> TACs


Referee 2
L99: mmm-1 is quite confusing; please add a space where appropriate.
LL162: what is delta-hat? On L162 if seems to be “change in the highest astronomical tide (δ-HAT)”, whereas on L163-164, we’re told that “…the full tidal range (δ-HAT).” I assume it is the astronomical tide, but this could be clearer.


Forwarded comment
John - you will have had my review through the system. I didn't pick up on them not resolving the overtides as xxx commented on. See below. I don't know if he will reply to you himself.

“Re:Devlin... I just glanced at it. I noticed that they didn't really learn anything from my comment. Figure 9 still has annual estimates of tides like MO3 which are affected by close frequencies, but now added together with a bunch of other compound tides, perhaps in the hope that if you add together a bunch of dubious time series you'll end up with something legit.”


Editor comments.
Regarding Figure 9 and overtides, I am not expert (Referee 1 and the commenter are) but I do know that most of your subscript-4 (and subscript-3?) constituents are from non-linearity, whereas M6 is mainly from friction on the M2 flow. There might even be some forcing from higher-order astronomical terms. So I do doubt the value of figure 9c. You don’t conclude much from it and I think any gain in understanding would need grouping of the constituents according to their origin (non-linearity, friction, . .).
Line 310. “multiple tides” -> “multiple tidal constituents”?

Dear Authors
Thank-you very much for your re-revised manuscript and all the attention to the reviewers’ comments.
Inevitably on reading it through again I have a few more comments. Please see “Detailed comments” below. These are “Technical corrections” meaning that you should deal with these and then enter the manuscript in the Copernicus/OS publication system directly with no more intervention by myself. There will be copy editing and you should check that the final version keeps you intended meaning.
Thank-you for submitting to Ocean Science.
Yours sincerely
John Huthnance

Detailed comments.
Lines 28-29. You won’t need these!
Line 49. “. . under MSL rise. Overall . .” ?
Line 92. Better “Pacific; TAC quantifies . .” ?
Line 93. Better “Devlin et al., 2017a); they found that . .”?
Line 100. Better with “,” after “statistics”
Line 103. Better “A recent paper performed a similar analysis in the Atlantic . .” or “A recent paper took a similar analysis approach in the Atlantic . .”

Lines 143-144. Delete one of the two “all”
Line 171. “. . seem valid . .” or “. . seem to be valid . .”
Line 176. “. . which is more apparent . .”
Line 182. “. . The approximation δ-HAT . .”??
Line 184. “. . largest tidal constituents (M2, S2, K1, and O1) . .”

Line 269. “. . The overtides (OT) band . .” (unless you meant to delete this sentence).

Lines 328-329. “. . may lead to larger tides . .” ? [Not clear that the forcing changes].
Line 333. “constituents . .”
Line 355. “quickly” -> “briefly”
Line 368. “but not as much for the δ-HATs.” If you mean that TAC was more significant than δ-HAT change, then better “but δ-HAT changes were less significant”. If you mean that δ-HAT change was more significant than TAC, then “but not as significant as the δ-HAT changes.”
Line 373. Omit “may also be a factor”

Line 756. Add “,” after “codes”