Which material is known for floating on water?

HMPE, or High Modulus Polyethylene, is known for its unique combination of properties, which include being lightweight and having a very high strength-to-weight ratio. One of the notable characteristics of HMPE is that it has a lower specific gravity than water, allowing it to float. This feature makes HMPE particularly useful in applications where buoyancy is beneficial, such as in rescue operations or marine environments where the equipment needs to remain above water.

Nylon and polyester have a higher specific gravity than water, causing them to sink. While hemp is a natural fiber that has properties similar to those of nylon and polyester in terms of density, it typically also sinks when placed in water. The choice of HMPE is significant in rescue operations, as it enhances safety and efficacy by allowing equipment to remain accessible and visible on the water's surface.