Having a dog as a companion is well worth the trouble and expense.
Mr. Utterson sometimes seems to appear envious of those who don’t follow the rules
Answer: It would be ocean's
Explanation: In this context the apostrophe show ownership, or WHOSE waters became choppy (I know an ocean is a WHAT and not a WHO but phrasing it like this in my mind always helped me). Without the apostrophe it would be the plural form of OCEAN.