It is recognised that small vessels, often made of glass fibre reinforced plastic (GRP), can be poor reflectors of radar signals. In situations where radar is the prime observation tool used by ships at sea, the International Maritime Organisation considers that it is essential that small vessels, considered in this context to be those under 150 gross tonnage, be equipped with a radar reflector to enhance their radar return and thus improve their visibility to radar.
ISO 8729-2:2009 specifies the minimum requirements for a radar reflector intended to enhance returns from small vessels as required by IMO Resolution MSC.164(78).
It provides the specification for the construction, performance, testing, inspection and installation of such radar reflectors.