Which vessel would be required to show a white light from a lantern exhibited in sufficient time to prevent collision?

The requirement for a vessel to show a white light from a lantern in sufficient time to prevent collision primarily pertains to the visibility and identification of the vessel's position and intentions, especially in low-visibility conditions. In this case, the correct choice is a power-driven vessel at anchor.

A power-driven vessel at anchor is mandated by the navigation rules to display a white light to make its status clear to other vessels in the area. This helps ensure that other vessels can see it from any direction and avoid a potential collision, especially important during nighttime or in conditions where visibility is compromised.

Other vessel types, such as a rowboat, a sailing vessel under sail, or a barge being towed, have different requirements for lighting at night or during poor visibility. While each has specific standards they must meet regarding navigation lights and signaling, the specific requirement for displaying a white anchor light is unique to at-anchor scenarios for vessels that are powered. This helps protect not only the anchored vessel itself but also passing vessels navigating nearby waters.