On which route is a towing vessel over 39.4 feet in length NOT required to carry an echo-sounding device?

Correct Answer: Option C — Western Rivers

46 CFR 27.100 exempts towing vessels operating exclusively on the Western Rivers from the requirement to carry an echo-sounding device. This exemption recognizes the unique operational environment of the Western Rivers, where traditional depth sounding equipment may be less effective or necessary compared to other coastal and inland navigation routes.