18meter

18meter is a term that can refer to more than one concept, depending on context. It is most often encountered as a measurement, denoting a length of 18 meters.

In sailing, the 18-metre class, written as 18mR or 18-metre class, was an International Rule-based design category used in the early 20th century. Yachts were designed to attain an 18-metre rating according to a formula that combined length, beam, sail area, and other factors. Because the rule is a rating rather than a strict length limit, vessels of varying hull shapes and sizes could compete within a single class. The 18mR class supported international regattas and contributed to developments in naval architecture before the rise of more modern measurement systems.

In general usage outside maritime contexts, 18 meter may describe any object or structure measuring 18 meters in length, height, or span, such as cranes, towers, or building components. Some companies, products, or projects also adopt 18meter as a brand name or model designation, but such usage is unrelated to the yacht class.

Because 18meter can refer to distinct concepts, readers should rely on context to determine the intended meaning. See also references to metre-based sailing classes and unrelated uses in branding or architecture.