Final answer:
Inconspicuous, partly submerged vessels or objects being towed should display a yellow all-round light for visibility and safety.
Step-by-step explanation:
The light that should be displayed for inconspicuous, partly submerged vessels or objects being towed is a yellow all-round light. This is required by maritime navigation rules to help other vessels identify and avoid towed objects or vessels that may be difficult to see, especially during night time or in poor visibility conditions. An all-round light is a light showing an unbroken light over an arc of the horizon of 360 degrees, meaning it is visible from any direction a vessel might approach.