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It turns
out the International Marine Organization (IMO) shares my sentiments.
In its safety requirements for international commercial (SOLAS) vessels,
the IMO requires boats under 150 gross tons to carry a reflector that
meets certain standards of what’s called Radar Cross Section (RCS).
To measure
RCS, radar echo measurement equipment is calibrated to a precision steel
sphere. Then a reflector is tested from every angle around the horizon,
resulting in a plot of effective RCS in the form of an irregular circle.
(The classic cornered radar reflector generates flower pedal plots.) The
IMO requires a mandated vessel to show a 10-square-meter RCS area from
at least some angles and a minimum of 2.5 square meters everywhere else.
Amazingly, only one passive reflector currently meets this standard, the
Cyclops 3. Within its 10"Hx17"Wx18"L fiberglass case, the
Cyclops has “di-electric lenses” capable of refocusing and
returning radar pings. The technology was invented by the British Ministry
of Defense and during the Falklands war was hung beneath helicopters and
worked well enough to lure radar-guided Exocet missiles away from their
targets.
Given
British weather and Channel traffic, it’s no surprise that another
innovative radar reflector also comes from the U.K. The Sea-me radar target
enhancer, produced by a small company of the same name, sells in the same
$500-to-$600 range as the Cyclops 3, but looks and works quite differently.
Proprietor Peter Munro was an early-retired aerospace engineer when a
heart-stopping 150-foot close call with a coaster off the island of Jersey
in fog “inspired” him. He chose an “active” technique,
in which a receiver listens for incoming radar pulses, amplifies them,
and sends them back out. The technology is not new, but Munro’s
goal was to improve the level of performance versus size and price. He
feels he has achieved this goal with the Sea-me.
The
Sea-me has been tested at 63-square-meter maximum RCS with no point showing
less than 10 square meters, easily exceeding the IMO’s present requirements
for passive reflectors. Real world users quoted on Sea-me’s Web
site report noticeable effects, like being seen at 12 miles even in wave-cluttered
seas. Another feature is the red “activate” light on its control
box, which will provide a head’s up if traffic enters a radar-quiet
part of the ocean. The Sea-me is not perfect. Though installing its 18"x2"
antenna wand on a powerboat should be trivial, I’d be inclined to
paint over its rather emphatic branding beforehand. More importantly,
Sea-me only works with X-band radar. X-band is far and away the most common
type of radar, and all SOLAS ships are required to carry it, but many
also carry an S-band set, which they tend to use more in rainy conditions.
So,
should you go out and buy a high-powered radar reflector? Not necessarily,
but it’s certainly prudent to check out your own vessel’s
inherent RCS. The ideal is to go out with a friend who also has radar
and target each other at different ranges and headings. Remember that
performance may be considerably diminished in rough seas. Ultimately,
it’s up to you how big you want to look, but bear in mind that the
IMO is concerned enough that it may soon triple its already challenging
RCS minimums. Very few yachts are SOLAS vessels, but we all share the
same oceans.
It’s
also worth considering that for some boaters out there you might be the
scary vessel that doesn’t see them. Study the RCS of any “small”
boats you come upon when the visibility is good; excercise may teach you
how to get the optimum target images from your set, and what might be
missing when the fog does roll in.
On a
final note, I’d like to issue a disclaimer. It seems I’ve
written a string of columns concerning gloomy safety issues, but I certainly
do not want to scare anyone away from boating. Being offshore, even at
night, even in fog, can be beautiful and memorable and safe. Statistically,
messing around in canoes or PWCs is more dangerous. But what the statistics
don’t record are yachtsmen’s anxiety levels; inexperience,
weather, and poor equipment can all conspire to suck the pleasure out
of pleasure boating. If my cautionary columns help anyone increase their
knowledge and confidence at the helm, that’s a good thing.
Sea-me
Phone: (44) 01963 34184. Fax: (44) 01963 32604. www.sea-me.co.uk.
North
Sea Navigator (Cyclops U.S. distributor) Phone: (631) 757-7169.
Fax: (631) 912-0748. www.northseanavigator.com.
Ben
Ellison has been a delivery captain and navigation instructor for nearly
30 years and was recently editor of Reed’s Nautical Almanacs.
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