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Amp up your boat’s visibility on radar with a simple reflector. Here’s everything you need to know about choosing, installing, using, and maintaining one.
Adding a radar reflector on a fiberglass or wood boat can enhance how well your boat is seen on radar. Photo. Frank Lanier
Visibility on the water can diminish rapidly due to fog, darkness, or foul weather. For boaters, especially those on smaller vessels made from fiberglass or wood, which don’t reflect radar signals effectively, radar reflectors can be life savers. In this article we’ll explore the purpose of radar reflectors and discuss the different types available, while providing selection tips and practical advice on installation, use, and maintenance.
The Benefits Of Reflection
While larger, metallic ships inherently possess a strong radar signature, smaller boats may appear as mere “blips” or even go unnoticed on the radar screens of approaching vessels. That’s where a radar reflector or Radar Target Enhancer (RTE) becomes a crucial piece of safety equipment. The benefits of using an RTE include:
1. Increased visibility. Small boats can be hard to spot visually, especially from the bridge of a larger vessel. Radar reflectors significantly improve a boat’s radar signature, making it easier for other vessels to see you.
2. Improved collision avoidance. In challenging conditions, where visual detection is limited, radar reflectors are crucial for ensuring your boat is detected by radar, reducing the risk of collision.
3. Meeting regulations. Some regulations, such as the International Regulations for Preventing Collisions at Sea (COLREGs) require smaller, nonmetallic hulled vessels to carry passive radar reflectors for use under certain conditions (i.e., while operating in heavy traffic areas, at night, or during inclement weather), if practicable for the vessel.
Radar is a key tool in collision avoidance, but only if it can pick up your boat.
How They Work
Marine radar works by emitting pulses of electromagnetic waves (microwaves) and detecting the waves that bounce back (echoes) from objects in their path. The specific angles of the surfaces of an RTE are designed to reflect a significant portion of the radar waves back toward the radar source. This makes the radar return for the reflector (and thus the boat) appear significantly larger than it is, making it more noticeable on the radar screen.
Types Of RTEs
Radar reflectors can be divided into two broad categories: passive and active.
- Passive RTEs (the focus of this article) use a series of intersecting metal plates, often arranged in a triangular or cylindrical shape, to create a strong reflection.
- Unlike passive RTEs, which simply reflect radar waves, active RTEs emit a signal that enhances radar return, making the boat more visible. Active reflectors can also alert you to the presence of other vessels’ radars. Downsides to active RTEs include significantly higher cost and more complex installation requirements than passive RTEs.
It Pays To Be Passive
Two common styles of passive RTEs are octahedral corner reflectors and tube-style reflectors.
Photo, Getty Images
- Octahedral corner reflectors consist of multiple corner reflectors (typically three) arranged in an octahedron shape. This design allows them to reflect radar signals from a wide range of angles, making them more forgiving of vessel orientation and more reliable when the boat is heeled or not perfectly upright.
- Tube-style RTEs are cylindrical or tube-shaped and typically consist of a series of intersecting metal plates or panels. They rely on a specific orientation (usually upright) to be most effective. Tube-style RTEs are compact, lightweight, and offer minimal wind resistance, which in turn reduces potential chafe on your boat’s gear (e.g., sails, lines). As to downsides, they require more precise mounting orientation than octahedral corner reflectors. If not perfectly upright, their reflective properties can diminish significantly.
Photo, Davis Instruments
Choosing An RTE
Regardless of which type of RTE you select, the next consideration should be size. Larger radar reflectors generally provide a stronger radar reflection. Performance is measured by radar cross section (RCS), and a higher RCS value indicates better reflection. The RCS of a reflector increases by the fourth power of its radius, meaning a reflector twice the size of a similar smaller model can have a 16 times larger RCS. As such, you’ll want to select the largest RTE your budget and vessel can accommodate.
Tube-style reflectors are lightweight, compact, and offer minimal wind resistance. Photo, Frank Lanier
Installation Considerations
Proper installation is critical to maximize the effectiveness of an RTE. When planning your installation, keep the following points in mind:
1. Height. Mount the radar reflector as high as possible. The higher it’s mounted, the greater its potential range. Aim for at least 4 meters (13 feet) above the waterline, but ideally as high as possible without compromising stability or interfering with rigging or other equipment.
2. Mounting. Consider how and where you’ll mount the reflector. Options include mast mounts, shroud mounts, radar arch mounts, or dedicated pole mounts. Hoisting them aloft via a spreader halyard on sailboats is also a popular option for temporary installations. For powerboats, a radar reflector should be located above all superstructures. The higher you can position the reflector, the less chance it will be blocked by your boat’s equipment or superstructure and the better it will perform. For permanent installations, ensure the reflector is securely mounted per the manufacturer’s instructions using appropriate hardware.
3. Orientation. Follow the manufacturer’s instructions for proper orientation, especially for reflectors with specific directional requirements. Proper alignment is critical for optimal performance for tube-style reflectors, while some corner reflectors are designed to be mounted in a “rain catch” position for improved performance.
4. Unobstructed placement. Ensure the reflector has a clear line of sight, one free from obstructions such as other boat structures or equipment – especially important for passive reflectors.
5. Vessel movement. For sailboats, consider the effects of heeling and choose a mounting position or a reflector design that minimizes performance degradation at varying heel angles.
Maintenance
Regular maintenance ensures your radar reflector remains effective. While you’ll want to follow the maintenance outlined in your owner’s manual, at a minimum it should include periodic cleaning with fresh water (to remove salt and debris) along with inspection of the mounting hardware and the reflector itself for signs of wear, damage, or corrosion. Replace any damaged or compromised components promptly.
Finally …
Choosing the right type and size RTE and ensuring it’s installed properly can significantly enhance your boat’s visibility and improve safety on the water. Keep in mind, however, that a radar reflector is just one element of a comprehensive safety strategy; maintaining a proper lookout and practicing safe navigation techniques remain essential at all times.