sat-dog

The correct answer is $348$. It's given that $1$ fathom is equivalent to $6$ feet. Therefore, $58$ fathoms is equivalent to $\left(58 \text{fathoms}\right)\left(\frac{6 \text{feet}}{1 \text{fathom}}\right)$, or $348$ feet. Thus, when the camera is at a depth of $58$ fathoms, the camera's depth, in feet, is $348$.