Which of the following is NOT a wreckage hazard?

Low water temperature is not considered a wreckage hazard in the context of diving. While cold water temperatures can pose challenges to divers, such as increased risk of hypothermia or requiring thermal protection, they are not directly related to the dangers associated with wreck diving itself.

Wrecks often pose specific hazards that divers must be aware of. For instance, falling objects can be a significant concern due to the structural instability of wrecked vessels. No direct surface access can create problems for divers needing to return to the surface quickly in case of an emergency. Silt can obscure visibility and may cause buoyancy control issues as well as potential disorientation while navigating around wrecks.