Thank-you for your revised manuscript addressing the referees’ comments. I am now asking you to consider the “Technical Corrections” below after which it will go directly to the Copernicus publication process. This will involve copy editing which I expect will make changes to the use of English. Please therefore check that the final version keeps your intended meaning.
Thank-you for submitting to Ocean Science.

Page and line numbers numbers are as in the 2-column version that I now have.

Page 1.
Line 50. Meaning of “respective region” unclear. Delete “has”.
Line 55. “. . April 27, 2014,” ?

Page 2.
Line 35. “what” -> “which”.
Line 81. “walking” -> “walk”.
Line 94. “which could have reached . . by July 29, 2015 and could have been subjected . .”

Page 3.
Line 15. “. . other hand, the large study domain . .”
Line 29. “. . ellipsoid, as follows”

Page 5.
Line 27. Better “. . in one of the four ensembles of simulations (section 2.2).” ? [To reinforce the relation of this section to what follows.]
Lines 45 and 52 imply σ**2 = 1/2. I might not have followed the statistics correctly but this seems to be a choice affecting the distribution in figure 3, which looks to have most leeway factors less than those mentioned in section 2.1.3, and likewise mostly less than the 3.29% or even the 2.76% of the other ensembles in section 2.2. Does this give the random leeway factor ensemble a bias towards wind-forced motion? Information about the sensitivity of the results to this is of course available in the results of the four ensembles of section 2.2. Maybe a short comment about this could be added, at the end of section 3 or in section 4?

Page 6.
Line 14. “. . in a variety . .”
Line 17. “. . displacements exceeding . .”
Line 57. “Close to a shore . .”? [delete “the” in any case]
Line 65. Delete “of”.
Line 72. “arithmetic.”

Page 7.
Line 2. “scenarios”. This should be the same word as later where “model” is mostly used (e.g. lines 12, 14; also in figure 5). I am not sure that “model” is the best word but is probably the most practical. Then better (for line 2) “Four scenarios – hereafter “models” – with respect to . .”).
Line 19. “The study domain extended from 20°E . .”
Line 28. “The following datasets were used in this study . .”

Page 8.
Figure 5 caption. “. . originating from . . for two models . .”
Line 29. “. . from nine . .”
Line 39. Delete “of”

Page 9.
Line 11. “what” -> “which”.
Line 22. “. . originating from . .”
Line 25. “. . originating from”

Page 11.
Line 55. “. . as of April 2017 . .” [meaning any time up to April; not only in April]
Line 58. “at Thirsty Point. . .”

Page 13.
Line 1. “An example of the so-estimated concentration . .”
Line 11. “. . concentration near Cape Leeuwin”
Line 18. “. . landed near Thirsty Point . .”
Line 28. “. . object, it had covered a long distance . .”

Page 14.
Lines 35-37. Better order might be “Considerable beaching, particularly in Australia and Sri Lanka where no fragments were found; . .” However this does give a slightly different emphasis which you may not want. Otherwise, please remove “,” after “beaching”.
Lines 40-42. Similar (but not quite the same); please remove “,” after “countries”.
Line 44. “. . originating from . .”
Line 51. “to Thirsty Point.”
Line 62. “declares”
Line 63. “Acknowledgements. Use . .”