Question

if the relative clause in bold is nonrestrictive, set it off with a comma. if it is restrictive, submit the text without making any changes. gavin steered his rowboat quietly past the fishing boats and went unnoticed by everyone, except for the man whose fishing line became hopelessly tangled around gavins oar.

Explanation:

The relative - clause "whose fishing line became hopelessly tangled around Gavin's oar" is restrictive as it is essential to identify which man noticed Gavin. It provides necessary information to single out the particular man. So, no change is needed.

Answer:

Gavin steered his rowboat quietly past the fishing boats and went unnoticed by everyone, except for the man whose fishing line became hopelessly tangled around Gavin's oar.