DAVIS EchoMaster Radar Reflector User Manual
Features, Installation, Design Principles
R155E
$1.00
Contents
Why Use a Radar Reflector? . . . . . . . . . . . . . . . . . . . . . 2
Echomaster™ Radar Reflectors . . . . . . . . . . . . . . . . . . . 3
How a Ship’s Radar Sees Your Boat . . . . . . . . . . . . . . . 4
Echomaster Specifications . . . . . . . . . . . . . . . . . . . . . . 4
Radar Reflector Design . . . . . . . . . . . . . . . . . . . . . . . . . 6
Reflectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Radar Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Radar Cross Section . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Plate Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Alignment of Reflector Plates . . . . . . . . . . . . . . . . . . . . 9
Installing Echomaster
Positioning the reflector . . . . . . . . . . . . . . . . . . . . . . .10
Assembling the reflector plates . . . . . . . . . . . . . . . . .11
Mounting Echomaster #152 . . . . . . . . . . . . . . . . . . . .12
Mounting Echomaster #153 . . . . . . . . . . . . . . . . . . . .13
Suspending the Echomaster from a spreader . . . . . .14
Using the #157 Surface Mount System . . . . . . . . . . .15
Echomaster Maintenance . . . . . . . . . . . . . . . . . . . . . . . .16
Why Use a Radar Reflector?
Collision avoidance is surely the most important part of enjoying the boating world.
Small and medium-sized boats are surprisingly poor targets for radar reflection and
are frequently in danger of being overrun by larger vessels, even under good visibility
conditions.
The radar display on a ship
will typically show sur-
rounding conditions for at
least 12 nautical miles (22
km), with gain and sea clut-
ter controls for adjustment.
But boats of today, with
fiberglass hulls and sleek
designs (curved or slanted surfaces reflect much less), do not possess enough
reflective qualities to make them highly visible on a radar screen.The response may
be small, weak or intermittent. Even a boat’s metal mast (a curved surface) and
engine (mounted low, in the realm of sea clutter) do not possess enough reflective
qualities to make the boat highly visible to radar. And container vessels and tankers
require long stopping time and wide turning radius. Ensuring the detectability and
recognition of your craft at a long distance from an overtaking vessel under all
weather and sea conditions is critical to avoid disaster. Without a radar reflector (or
radar of your own) you’re left to peer into the fog or darkness or listen for bells,
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foghorns, propellers, or the mighty bowwave from an onrushing “skyscraper of steel.”
Even if you did spot them or detect them on your radar, which way would you turn?
Best to let them “see” you instead.
Furtherrnore, in distress situations the Coast Guard can be materially aided in search
and rescue by the deployment of a good radar reflector. The U.S. Coast Guard is
considering marine radar reflector requirements that would apply to pleasure boats
operating in waters of the United States. Already such laws exist in many other coun-
tries such as the United Kingdom, Canada and Germany.
Radar reflectors may also be mounted on a buoy or piling to help identify your dock or
mooring in less than perfect conditions. They can also supplement official markings on
hazards to navigation such as bridges, rocks, submerged trees, sunken boats.
Make your boat visible…
Find your way home…
Mark hazards to navigation
Echomaster™radar reflectors give ships a chance to see your boat in fog and low vis-
ibility conditions—a must for serious boaters. The Echomaster circular plate radar
reflector is the most practical, efficient, and cost-
effective reflector available to pleasure boaters.
Echomaster’s superiority is proven. It was
ranked one of the world’s best radar reflectors
and one of the top ten sailing products by
Practical Sailor. SRI rated Echomaster “superior”
after the most rigorous tests ever conducted on
radar reflectors, some costing 10 times as much.
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How a Ship’s Radar Sees Your Boat
The radar of a ship making a complete circle around a boat would hit the boat’s
radar reflector from all angles. If the boat were stationary and we plotted how strong
the reflected signal is at all angles, we would arrive at performance diagrams such
as this…
DAVIS
ECHOMASTER
#152, 153
DAVIS
EMERGENCY
RADAR
REFLECTOR
#151
MOBRI RADAR
REFLECTOR
Admiralty surface weapons test, England
FIRDELL
BLIPPER
RADAR
FLAG
The outside of the circle is what a 102meter cross section of a metallic sphere
would reflect—the laboratory standard. The larger the performance plot, the better
the radar reflector. Peaks in the pattern should approach the laboratory standard and
be uniformly distributed 360° around the fixed reference point (your boat). Valleys
should be minimal in width. The Davis reflectors show good balance: strong peaks,
narrow valleys. Other reflectors have inadequate peaks or large areas of weak
response, making them seem smaller on an oncoming ship’s radar screen.
Echomaster Specifications
Reflector plates are 12.5" (32 cm) diameter,
circular, aluminum. Plates provide 13.2
square yards (12 sq. meters) of maximum
effective radar cross section in the X or 3 cm
band (9–9.6 GHz frequency), based on opti-
mum orientation between the reflector and
radar. Echomaster offers equivalent radar
cross section of conventional triangular plate
reflector with approximate 17" (43 cm) diago-
nal dimension.
Plates are made of robust 0.05" (1.3 mm) marine grade aluminum; sufficient thick-
ness to minimize flexing. Dimples in plates allow corner latches to attach precisely,
minimizing angular distortion.
Windage holes reduce aerodynamic drag and allow assembly of the reflector around
a backstay. Windage hole size 1.25" (32 mm).
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Captive corner latches are tough, injection molded plastic to assure minimum angle
error. Corner latches allow reflector to be quickly and easily assembled and
demounted. Reflector stows flat.
Weight without mounting hardware: 1.65 lbs. (.75 kg). #153 mounting harness
weighs 1.5 oz. (.4 kg).
#152 Standard Echomaster
Aluminum plates. May be assembled
around a backstay, or make your own
bridle and hang from holes drilled in
corner latches. #157 Surface Mount
System can be purchased separately.
#157 Surface Mount System
Allows hard surface or rail mounting of
#152 or #153 radar reflectors. Base mea-
sures 2.75 x 3.75" (7 x 9.5 cm). Surface
or rail mounting makes sense on a hard
top, masthead or spreader, navigation
hazard, dock piling, or as an aid to navi-
gation.
#153 Deluxe Hanging Echomaster
Anodized aluminum plates. Comes with
hanging mount system to suspend unit
from mast or rigging in perfect “catch rain”
position. Vinyl storage case included. #157
Surface Mount System can be purchased
separately.
For Echomaster installation instructions, see page 10.
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