Visual EnhancementBy Lenny Rudow
Published: June/July 2011
Make sure other boats see you, no matter what conditions you're in.
Ever since some fog-bound Phoenician thought to hang a lantern from the beak of his bireme, we mariners have been searching for better ways to be seen. Whether fog, darkness, or driving rain is the culprit, a lack of visibility isn't only unnerving, it's dangerous, and savvy boaters will take measures to make sure their boat is as visible as possible. Otherwise, you could end up in a bad situation, thanks to the actions of others.
Enter technology. We've come a long way from that whale-oil lamp swinging in the foggy breeze, and today, becoming "visible" to other boats has a lot more to do with electronics than it does with human eyes. Before you shove off, no matter the forecast and no matter the time of day, make sure your boat has maximum visibility.
The number-one tool used to see through darkness and fog, by both commercial ships and recreational boats alike, is radar. That means you should consider your boat's visibility to radar, first and foremost. Unfortunately, fiberglass is a poor radar reflector. Worse, the curvaceous styling of many modern boats acts much like the radar-avoiding stealth designs used by the military. Those luscious, eye-candy curves tend to cause radar waves to glance off them, instead of being bounced back whence they came; 90-degree angles make for far better radar targets, but few are found on most of today's recreational boats.
Luckily, there's a quick and easy fix to this problem: Add a radar reflector to your boat. Radar reflectors come in two basic flavors: passive and active. Passive reflectors can be single or multi-element (multi-elements work better in varying positions, and thus are more effective for heeling sailboats or powerboats rolling in a heavy sea) and they work by offering those radar waves an optimal surface to bounce off. Active target enhancers, on the other hand, work by electronically amplifying the radar waves they receive before sending them on the way back to their source. Though they are extremely effective, they're also expensive (upwards of $1,000) and require a complex installation; in virtually all cases, recreational pleasure boaters will go passive.
Passive reflectors are fairly inexpensive (starting at about $30 at West Marine for an economy version from Davis) and are available in many different shapes and sizes. Deck, mast, rigging, and tower-mounting options are all Ocean Equipment Echomax offered, covering diverse types of boats from ocean-crossing schooners to centerconsole fish boats. They don't have to appear obtrusive, either. Some, like the Ocean Equipment Echomax, are ensconced in a polyethylene casing. Your eyes see a clean, white, round cylinder, but radar sees the laser- cut aluminum beneath the plastic skin.
On the screen of another boat's radar, these passive reflectors provide a solid target in calm conditions. Remember that the more the boat moves, however, the less effective that reflector is. As the radar waves hit and then miss the reflector, another boat will see you appear and disappear intermittently on-screen. It's not perfect, but it's a big step up from not appearing at all, or only appearing at very close ranges. And the only way to combat this flaw is to upgrade to a multi-element reflector. That means that those who ply coastal waters and venture offshore only on rare occasions, and boaters who usually stay close to home or merely sit at the dock when visibility is restricted, can get by with a small, inexpensive passive reflector. If you plan on long-distance cruising or are a bit bolder about casting off regardless of conditions, however, consider a multi-element reflector that provides you with more reliable visibility. If you're a die-hard boater who spends more time at sea than on dry land, an active reflector, which virtually always provides a solid target at extended ranges, is probably worth the extra cash.
One of the newer and most effective ways to be "seen" is actually to be heard — by another boat's AIS (automatic identification system), that is. When a boat receives your AIS signal, you appear on their receiver or chart plotter screen along with pertinent data about your boat, and when your unit receives their signal, their boat and data appear on your screen. The system is fairly simple and highly automated; once your unit is programmed, it sends out your signals via VHF, all on its own.
There are two classes of AIS transponders: Class A and Class B. Class A are required on large commercial ships, put out more power (generally about 12 watts), include comprehensive data (including a ship's name, course, speed, size and type, destination, and more), and they make their transmissions every two to 10 seconds. Class B units are far more common on recreational vessels, put out less power (about two watts), transmit a reduced amount of information about the vessel, and transmit every 30 seconds. Class B units also cost far less than Class A, and units like the West Marine AIS 1000 can be found for as little as $499.
There's also a third form of AIS: receive-only units. These are exactly what they sound like, and although they do give you the ability to see the other vessels that are transmitting an AIS signal, they don't help you get seen at all. The major electronics manufacturers offer Class B and receive-only AIS units, and some even package them with other electronics. Most multifunction displays have an AIS option, and one nifty unit produced by Standard- Horizon, the Matrix AIS ($399), combines an AIS receiver with a VHF radio. This provides some added utility because it allows you to "tag" AIS targets on-screen and communicate with them directly, via DSC.
That might not make your boat appear on their screen, but it does allow you to tell them you're there.
To gain understanding of just what AIS can do for you in either its Class A, Class B, or receive-only form, check out www.marinetraffic.com/en/. This website gives you access to the information being broadcast by thousands of ships in real time, all across the globe.
When you've already encountered a problem and need to be seen by search and rescue (SAR) personnel, you want to stand out in every way possible. There's a new way to appear to the electronic eyes of SAR vessels: AIS SART units. Unlike the EPIRB and satellite messenger emergency systems you're already familiar with, a SART (search and rescue transmitter) can be found with an AIS transmitter already built in, alongside an internal GPS antenna. The SART unit appears as a series of blips on a radar screen, providing rescuers with a direct bearing to your location. At the same time, with these new units, SAR personnel will receive the AIS data just as they would from a ship so they'll know your exact location, speed, and direction of drift, and other critical data. Added safety bonus: Any AIS receiver-equipped boat or ship in the area, as well as the SAR team, can see you onscreen. So if you're well offshore and miles away from the nearest rescue station, but there's a commercial ship or a recreational boater with AIS nearby, they'll get your call for help, too.
AIS SART units are still new to the marketplace, and only offered by a handful of manufacturers. McMurdo has the S5 AIS SART (www.mcmurdo.co.uk), Jotron offers the Tron AIS-SART (www.jotron.com), and Kannad Marine (www.kannadmarine.com) produces the Safelink AIS SART. But considering how useful these little devices are, we're sure to see their availability increase sooner rather than later.
Can You See Me Now?
One of the simplest ways of making yourself visible is also one of the most neglected: your running and anchor lights. Yes, it's time to get back to basics, because even with all of our modern electronics, it's the eyeball that often makes the final call when avoiding collisions or locating other boats. It may seem like there hasn't been much of a change in the all-around whites, reds, and green; in fact, there's been an illumination revolution going on: LEDs.
Like incandescent bulbs, LEDs come in varying levels of brightness (and of course, brighter is always better when it comes to being seen). These LEDs, however, hold some other advantages that may make it worth considering an upgrade for the lights on your boat. The first is reliability. Bulbs burn out with startling regularity, usually just when you need them the most. LEDs, however, generally have a life span of 50,000 to 100,000 hours of burn time before they require replacement. Most are also sealed in their fixtures, which makes them impervious to the corrosive atmosphere. And the lights themselves are colored, so you don't have to worry about broken or lost lenses turning your reds and greens into whites. Finally, LEDs draw far less power than incandescent bulbs. While a common anchor light draws between 0.6 and 0.9 amps, LEDs draw 0.1 or 0.2 amps, reducing the light's impact on your house batteries (see Foundation Findings #48 at www.BoatUS.com/Foundation)
Lights should also be considered for personal visibility. If you end up in the water and separated from your boat for any reason, a light could mean the difference between life and death. Strobes, like the West Marine Aqua Strobe ($42.99) and the ACR Firefly ($33.99), which you can and should clip onto each and every life jacket on your boat, are both waterproof and highly visible.
Increasing your boat's visibility increases your safety margin, and thanks to modern technology, you can make your boat significantly easier to see both onscreen and to the naked eye — even when the fog's so thick you can't see a bireme from 10 cubits away.
Lenny Rudow is electronics editor for BoatUS Magazine.
Retrofitting your boat with LED lights will cut the amount of energy used to light your boat by 90 percent
AIS has come of age for recreational boats by automatically communicating course and speed to other vessels
No matter how powerful your radar is, its performance may be limited by the way the antenna is mounted