Sea-Me Active Sea-Me Radar Target Enhancer

The Sea-Me Active Radar Target Enhancer is an active system which receives a radar signal, amplifies it and re-transmits it.

This ensures a stronger return signal and a more even strength around the full 360° azimuth. The Sea-Me unit is supplied on an antenna which can be mounted as high and free of obstruction as practicable.

A stand-off mounting for masthead fixing is available.

Active radar reflectors have the following advantages over passive radar reflectors.

1. Greater detection range
2. More consistent return
3. Better performance in clutter
4. Better performance at heel
5. Automatic ship detection alert

Why Do You Need a Radar Target Enhancer?

Most yachts and motor cruisers are today made of GRP, an inherently poor reflector of radar signals, the prime tool used by ships to see us. For our own safety and peace of mind we should do all that we can to enhance our return signal and thus increase the probability that it will be seen consistently. The Sea-Me Active Radar Target Enhancer is the modern solution to this problem.

Why Fit the Sea-Me Radar Target Enhancer?

Your safety depends on being seen, day and night, fair weather or foul.

Radar is the prime tool used by ships to see. In any conditions, Sea-Me will increase the probability that you will be seen on radar.

At night, the range of the masthead light of a sailing yacht of less than 20 m LOA is only 3 nautical miles and of a sailing yacht of less than 12 m LOA only 2 miles. A ship making 20 knots will cover 3 miles in only 9 minutes - any steps you can take to give a vessel more time to avoid you are a must!

Sea-Me has a maximum radar cross-section of 63 sq m, some 6 times the current requirement for a passive radar reflector, and an average of 34 sq m.

Sea-Me is an ACTIVE system which emits a stronger signal than it receives. The detection range is thus increased.

The higher a reflecting device can be fitted, the better - Sea-Me is ultra light (weighing just 410 g) and can therefore be fitted at the masthead.

Sea-Me uses little power - just 150 mA on standby and 350 mA when it is transmitting.

Sea-Me, because it is active, tells you when you are being struck by a radar signal and therefore when a ship is in your area. A sounder can be connected to the control box so that you get an audible as well as a visual warning that you have been struck by a radar signal.

Sea-Me can be fitted to your boat using a standard 1-inch 14-thread per inch antenna mount (not included). Supplied complete with 24-m cable and full instructions, Sea-Me is easy to fit and to use.

The 5 Benefits of Sea-Me

The disadvantage of the passive reflector lies in the many directions in which its radar cross-section is low, resulting in a minimal return. The polar plot shows that Sea-Me has a much more even response pattern and suffers from none of the gaps so typical of a passive device.

1. Greater detection range

The strength of a radar signal falls off rapidly with distance. In the case of a passive reflector, this degradation takes place over a distance equal to double the range (radar to target and back) whereas in the case of an active device, which is itself a transmitter, it only falls off over the return distance - and from a much higher amplified signal level. This means that Sea-Me, an active device, has a greater detection range than the typical passive reflector.

2. A more consistent return

Ships today use a system known as ARPA (Automatic Radar Plotting Aid). This enables the radar to emit an alarm when it acquires a target within its guard zones and thus to alert the watchkeeper. Target acquisition will only take place if the radar receives returns on at least 50% of scans. Two factors contribute to a consistent return - the strength of the returned signal and, because small boats yaw and heel, particularly in rough seas, the evenness of the return.

3. Better performance in clutter

Performance in clutter (rain and high waves) is all about signal strength. The single fact that Sea-Me emits a stronger signal means that it performs better in clutter.

4. Better performance at heel

The effectiveness of a passive reflector falls off rapidly as the boat heels, as you would expect of a device which is effectively a mirror reflecting in a single direction. The Sea-Me device shapes the beam to provide an effective return even when the boat is heeled.

5. Ship detection alert

Passive reflectors cannot give you any warning that you have been struck by a radar signal indicating that there is a ship in your area. Sea-Me, being active, knows when it has received a signal and can alert you with a flashing light, and if required, audibly. Sea-Me thus enables you to sharpen up your lookout when necessary.

Detailed Specifications

• Operating frequency: X Band (9.32–9.5 GHz)
• Dimensions of antenna unit: 416 mm long by 50 mm diameter
• Thread in base of antenna unit for antenna mount: 1 inch – 14 - NF
• Weight of antenna unit excluding cable and mount: 410 g
• Dimensions of control box: Outside diameter 112 x 64 x 33 mm
• Connecting cable (24 m supplied): BASEC approved 16 x 0.2 mm rated for 3 A at 300V 5.3 mm
• Maximum gain at 9.4 GHz: 58.9 dB
• Minimum gain at 9.4 GHz: 50 dB
• Polarisation: Horizontal
• Antenna vertical beam width (tolerance to heel): ±2.4 dB at ±15°
• Response time: 1.27 nanoseconds
• EIRP: Max 630 mW
• Power supply: 12 V DC
• Current consumption in quiescent state: 150 mA
• Current consumption when transmitting: 350 mA
• Control box fuse: 0.5 A Quickblow 20 mm