What does 'negative buoyancy' mean?

'Negative buoyancy' refers to the condition of an object that has a greater density than the fluid in which it is placed, resulting in the object sinking below the surface of the water. This means that the upward buoyant force exerted by the water on the object is not sufficient to counteract the weight of the object itself, leading it to descend.

In water rescue and aquatic scenarios, understanding the concept of negative buoyancy is crucial for rescuers when assessing the behavior of individuals or items submerged in the water. An object or person with negative buoyancy will not float; instead, they will remain submerged or sink, which could indicate the need for immediate intervention to prevent drowning or injury.

The other answer options reflect different buoyancy scenarios: an object that floats indicates positive buoyancy, one that is suspended shows neutral buoyancy, and an object carried by the current highlights external movement rather than buoyancy characteristics. Each of these describes a different interaction with water that is essential to understand for water safety and rescue operations.