Octahedral Radar Reflector. Aluminium models, fold flat for easy storage. 340 x 340 x 470mm. Weight 1000g. 7 m² reflective area complies RORC.
The following is some advice from the RYA website.
The ISO test standard to which radar reflectors must comply is currently under review, with the revised standard due around the end of January 2009. Until this revised standard is in force, radar reflectors available for use by pleasure craft, should meet the current ISO test standard 8729:1997 which in the UK is laid down in British Standard BS EN ISO 8729:1998.
Radar reflectors built to the current standard are often too large to be practically fitted to smaller vessels and it is with this in mind that the MCA have issued their guidance. They consider it to be feasible for vessels of 15m and over to fit radar reflectors that comply with the standard, but advise that vessels of under 15m in length should fit a radar reflector with the greatest echoing area practicable.
With this in mind the critical factors when selecting and fitting a radar reflector remain to ensure a device with the largest possible radar cross section is carried and that it is mounted in accordance with the manufacturer’s instructions. Generally speaking, the higher a reflector is mounted, the better, although vessel operators should take account of the possible effects of the mass of the reflector on the stability of the vessel.
The current IMO test standard 8729:1997 in very basic terms requires that a radar reflector has:
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a peak Radar Cross Section (RCS) of at least 10m²
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an RCS of at least 2.5m² over an azimuth angle of at least 240° when the reflector is vertical (i.e. not healed over)
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an RCS of at least 0.625m² over an azimuth angle of at least 240² for angles of heal up to +/-15°
Over the past few years there have been several trials carried out by the boating press, on how effectively recreational radar reflectors meet this requirements. All seemingly conclude that whatever their manufacturers might claim, some designs are little better than no reflector at all and even the most popular do not always come up to expectations, this is hardly surprising when the IMO requirement is fully understood. Laboratory test results have shown that average RCS values are often much lower than claimed and many reflectors have large nulls (areas where there are virtually no radar returns at all). The physics of radar reflection is complicated and it is notoriously difficult to conduct trials under real conditions at sea where conditions are less than perfect and reproduce test lab results. Given that the reflection from even the best recreational reflector is also affected by positioning, orientation and angle of heel, you may be starting to get the picture that you might not always appear on the [radar] picture!
The revised ISO standard will result from the new IMO requirement set out in resolution MSC 164(78). This new IMO resolution recognises that consistency of response is more effective in raising the probability of radar detection than single high peaks. This is defined as a “stated Performance Level” (SPL) and is required to be maintained at up to 10° or 20° degrees (two classes recognising the stability differences of power and sailing vessels) either side of the vertical.
The Maritime and Coastguard Agency (MCA) has issued a Marine Guidance Note on the carriage and use of Radar Reflectors on small vessels. MGN 349 is a notice to all Owners, Operators, Masters and Skippers of small vessels under 150 tons including Pleasure craft.
It can be read in full using the link at the top of the page, however in brief the recommendations made in section 4 are as follows:
It is strongly recommended that:
4.1 The requirements of SOLAS Chapter V Regulation 19 are complied with;
4.2 Yachtsmen permanently install, not just carry on-board, a radar reflector or RTE [radar target enhancer] that offers the largest Radar Cross Section (RCS) practicable for their vessel;
4.3 Small craft owners and operators are strongly recommended to fit the best performing radar reflector possible. It is also essential for skippers to be aware that, notwithstanding the type of radar reflector fitted, in certain circumstances their craft may still not be readily visible on ships’ radars. They should navigate with caution.
4.4 The following reports published by the Marine Accident Investigation Branch are considered during the process of selecting a radar reflector:
http://www.maib.gov.uk/cms_resources/Radar reflectors report.pdf
http://www.maib.gov.uk/cms_resources/Ouzo_Flyer to Leisure industry.pdf
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