Which condition may contribute to issue with equipment during a dive?

Worn-out seals can significantly impact the functionality and safety of diving equipment. Seals are critical components in preventing water from entering sensitive areas of equipment, such as regulators, dive computers, and buoyancy control devices. If the seals are compromised due to wear and tear, they can lead to leaks, reducing the effectiveness of the gear and posing safety risks while diving.

In contrast, backroll entry is a method of entering the water that generally does not have a direct correlation with equipment functionality. Clear water does not affect the equipment itself but enhances visibility, which can improve safety while diving. Proper maintenance is essential for ensuring equipment functions correctly, but it does not introduce issues; rather, it prevents them. Therefore, among the given options, worn-out seals stand out as a specific condition that can directly contribute to equipment problems during a dive.