What materials can be useful in creating makeshift flotation devices?

The choice of empty containers, wood, or anything buoyant as useful materials for creating makeshift flotation devices is particularly relevant in survival situations where access to traditional life-saving equipment may be limited. These materials are naturally buoyant or can trap air, which provides the necessary lift to keep individuals afloat in water.

Empty containers, like bottles or barrels, can be found in various environments and are designed to displace a considerable amount of water, which aids in buoyancy. Wood, especially light or hollow types, also has intrinsic buoyancy due to its structure, allowing it to float effectively. Similarly, other materials that can trap air pockets—such as certain plastics—can also serve the same purpose if they are not overly heavy or waterlogged.

In contrast, heavy metals and rocks are inherently dense and would sink rather than provide any flotation. Sand and pebbles, being small and heavy grains, do not provide buoyancy and would similarly sink. Rubber tires and plastic bags could be buoyant, but they are not as universally accessible or reliable as the combination of empty containers and wood, making that option the most practical for survival scenarios.