Thames Measurement

Thames Measurement, also known as Thames Tonnage, is a system for measuring ships and boats. It was created by the Thames Yacht Club, and was designed for small vessels, such as yachts. It was originally used for calculating the port dues for yachts; the formula was also used in some early handicapping systems for yacht racing.

The calculation of Thames Tonnage uses the following formula:

${ThamesTonnage}={\frac {({length}-{beam})\times {beam}\times {\frac {beam}{2}}}{94}}$

where:

• length is the length, in feet, from the stempost to sternpost;
• beam is the maximum beam, in feet.

This can be simplified as:

${ThamesTonnage}={\frac {({length}-{beam})\times {beam}^{2}}{188}}$

See also

Tonnage