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

Explanation:

The relative - clause "whose fishing line became hopelessly tangled around Sandeep's oar" is restrictive. It is essential for identifying which man is being referred to among all the people around the fishing boats. Without this clause, the identity of that particular man would be unclear.

Answer:

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