Jeez! You do come up with 'em don't you Norm!?😮
Testing me again?😉
Best I can do is the attached two pics.
One showing Rainbow, the other HMCS Niobe of the same era. Both at anchor with detail of the bow.
Incidentally; Niobe preceded Rainbow as the first HMCS ship by just two weeks.
Both pics seem to show the chain links as being as near as dammit the same length as the inner diameter of the portholes.
So I reckon if you take that as your guideline you won't be far wrong.👍
Cheers, Doug 😎