Serious Signaling

One of the undeniable delights of sailing is the isolation it affords. However, there are times when the company of others may be greatly sought after … when you need HELP! The manner in which you should try to obtain outside assistance depends on the urgency of your need. The most urgent need is best met using a radio transceiver: VHF, if within range of a shore station (or another vessel); cellular telephone, if within range of a cell tower; HF/SSB or a satellite communication system, if offshore. Unlike the situation 100 years ago, when a vessel out of sight of land or another vessel was truly alone, today’s voyagers need never be out of contact with the “outside” world.

Although all of the above-mentioned electronic communication devices and systems are available for even quite small vessels, U.S. and international regulations still require carriage of non-electronic means for signaling for assistance. U.S. requirements for carriage of emergency signaling equipment are defined by Coast Guard regulation. The rules govern all vessels used on coastal waters, the Great Lakes, territorial seas and those bodies of water connected directly to them, up to a point where a body of water is less than 2 miles wide. The minimum specified complement of distress signal devices must be U.S. Coast Guard approved.

Signal devices are categorized for day and night use, and requirements differ. Recreational boats less than 16 feet in length; boats participating in organized events, such as races, regattas or marine parades; open sailboats less than 26 feet in length and not equipped with propulsion machinery; and manually propelled boats are not required to carry day signals when navigating between sunrise and sunset. However, all craft, including those mentioned, must carry night signals when navigating during the hours from sunset to sunrise. (Why would anyone operate a boat in open water without carrying a day signal such as a distress flag or a signal mirror?)

Urgent need

A call for immediate assistance is usually a mayday call. Virtually all of the methods suggested for routine or less urgent calls for assistance can be used to send an urgent call for help; however, you can also use task-specific pyrotechnic devices: A hand-held flare, meteor flare or parachute flare can be used to attract attention to your need for immediate assistance. In daylight, a smoke signal, distress signal flag, signaling mirror or distress signal light can be used. However, regardless of which of these visual means you use, someone must see your signal and recognize it as a call for assistance, a sequence of events that can be frustrated by your position at the time of the distress or the inattention or confusion of those who might reasonably be expected to see your signal.

Image Credit: US Coast Guard/CWO Ken Gibson
While flares, smoke, and floating distress markers won’t attract rescuers from long distances, they are important rescue elements when searchers are nearby and need a final visual fix on your position. Above, Coast Guard personnel practice using smoke signals.

The only Coast Guard-approved non-pyrotechnic signal devices are: a distress flag at least 3 feet by 3 feet with a black square and ball on an orange background, meeting the requirements of 46 CFR 160.072, or an electric distress signal light that automatically flashes the international Morse code SOS signal and meets the requirements of 46 CFR 161.013. A signal mirror used properly in reasonable conditions can be a very effective means for alerting others to your need for assistance; however, these devices cannot be used to satisfy the Coast Guard signal requirements. (A compact disk can be an effective signal mirror in a pinch).

Image Credit: Coast Guard/RDC Al Emge
A Coast Guardsman fires an illumination parachute flare during training exercises in the Caribbean. While more expensive, SOLAS-approved rocket-type flares tend to be brighter and attain a higher altitude, increasing the chances you’ll be spotted by searchers.

Pyrotechnic signal devices must be Coast Guard approved and carry notice of the approval specification they meet. All such devices have a defined useful life of 42 months, and although expired signals can be carried onboard, they cannot be counted toward meeting the visual distress signal requirements for the vessel. Red flares, both hand-held and aerial, and parachute flares meet both the day and night requirements. Orange smoke signals meet only the day requirement. A minimum of three day and three night signals must be onboard vessels required to carry such signals.

Image Credit: Courtesy Greatland Laser
Greatland Laser’s Rescue Laser Flare is demonstrated in a misty room to show the laser beam. According to Greatland Laser, the laser can be detected by search aircraft as much as 16 miles away. The user slowly sweeps the laser past the aircraft and the flash of the passing beam is designed to catch the eye of the aircrew.

Different types of pyrotechnic signals are not equal in their ability to attract attention. The distance at which a hand-held flare may be visible depends in part on how high above the water the flare is when burning. To be really effective, a signal must be bright enough to alert someone to your need for assistance. In this regard, flares that meet the requirements of the International Convention for the Safety of Life at Sea (SOLAS, a set of equipment standards for merchant vessels) are much preferred since they are far brighter than the less costly non-SOLAS variety, providing luminosity ratings of 10,000 candlepower or more, compared with the 700- to 1,200-candlepower ratings of the flares most often carried by recreational vessels.

Attracting attention

In addition to its luminosity, a flare must also burn long enough to provide a homing reference for potential rescuers. Thought they are not as bright, a non-SOLAS flare will typically burn for about three minutes, compared with the slightly more than one minute burning time for the SOLAS variety. Given that SOLAS flares burn out more quickly, the Coast Guard requires that at least three flares be carried to provide a usable homing signal.

The daylight visibility problem that affects all flares can be somewhat overcome with the use of an orange smoke signal. Here, the SOLAS and non-SOLAS durations are the opposite of flares; SOLAS smoke units last longer. A Coast Guard-approved hand-held smoke signal will burn for one minute. A SOLAS-approved floating orange smoke signal is much preferred, since it will burn for at least four minutes and poses no risk of hot slag hurting the user or damaging the boat. Tests have shown smoke is effective even in windy conditions.

As noted, the visibility of a pyrotechnic flare depends in part on its elevation above the water. Red aerial flares that meet Coast Guard specifications are available in several forms: self-contained, one-time-use launchers; mini-launchers that accept separate flares; and 12-gauge and 25-millimeter flare guns. The typical 12-gauge aerial flare provides 15,000 candlepower for six seconds. The 25-mm gun can launch a 35,000-candlepower, seven-second burn time aerial flare, and red, 17,000-candlepower parachute flares with a burn time of 29 seconds.

While the performance of non-SOLAS flares and smoke signals may be suitable for many mariners, some see the significant additional cost of SOLAS-approved signals as a reasonable expenditure in return for the substantial performance increment they provide. For example, a SOLAS-approved red parachute signal rocket will typically reach an altitude of 985 feet and provide a minimum of 30,000 candlepower for at least 40 seconds. The SOLAS-approved hand-held flares, both red and white, have a shorter burn time than the typical Coast Guard-approved hand-held equivalent. These hand-held flares can get quite hot while burning, but they do not emit hot residue, making them the right choice for use in an inflated life raft.

An alternative to exclusive reliance on Coast Guard-approved pyrotechnic signals is available in the form of an automatic SOS signal light. One such light is the ACR product number 1842 night visual distress signal. This waterproof, floating light provides more than 50,000 candela, making the light theoretically visible for a distance of 22 miles. Carried in conjunction with an approved distress flag, the light will satisfy the Coast Guard minimum requirements for recreational vessels.

Another light signaling product is the Rescue Laser Flare from Greatland Laser in Anchorage, Alaska. This unit produces a laser beam that lets you to signal to searcher on ships or aircraft.

Standing out on radar

Mariners may find the idea of a device designed to attract the attention of a radar-equipped search aircraft of interest. A conventional vessel-carried passive radar reflector can be quite useful, as can a battery powered search-and-rescue transponder (SART). The signaling emergency aerial locator (SEAL), is a kite equipped with a radar-energy-reflecting 12-foot-long tail.

The effectiveness of visual distress signals is necessarily subject to great variation due to the intensity of the signal and the weather, visibility conditions, the background against which the signal is viewed, its elevation above the sea’s surface, wave action both on the vessel carrying the signal and that of the observer, and the duration of the signal’s illumination. A number of tests have been conducted to gauge the usefulness of commonly carried visual signals, including one conducted by the BoatU.S. Foundation in the waters of Chesapeake Bay, in conjunction with the Coast Guard among others. The test program and its findings are available on the BoatU.S. website, ( flares.htm) as Report 31, September 1998, Pyrotechnic Visual Distress Signals. The reported observations will assist your distress signaling decision-making.

All visual distress signals are subject to a common &mdash and, on occasion, fatal &mdash flaw. Someone must be both within visual range of your location and looking in your general direction if they are to take note of your signal. Recognition of this limitation, which was so tragically evident in the sinking of Titanic, led to the laws requiring the use of wireless radio distress signaling for all commercial vessels operating on the high seas.

The means for requesting emergency assistance have now evolved to the point where totally automatic fast-response systems are available for virtually any boat, including, in some cases, “vessels” as small as sailboards. (Sailboarder’s in the Cape Town, South Africa, area are required to carry small emergency position indicating radio beacons, or EPIRBs). Today, a prudent mariner will equip his or her vessel with a DSC-capable VHF radio, connected to a GPS or loran navigation receiver. Although the Coast Guard’s nationwide VHF distress monitoring system, Rescue 21, is not yet in full operation, a growing number of locations will go online in the coming months, and there are increasing numbers of other mariners whose vessels are equipped to receive and automatically alert their operators of your DSC distress call. In addition all SOLAS vessels are already equipped with Global Maritime Distress and Safety System equipment that includes both VHF and HF/SSB DSC receiving equipment.

Satellite relay

During the past 30 years, many mariners have equipped their vessels with EPIRBs that transmit simultaneously on the two international aviation distress frequencies, 121.5 and 243.0 MHz. Although often very effective in alerting the outside world to a distress situation, they suffered from two major shortcomings: The monitoring satellite system of Cospas/SARSAT could not store and forward signals at these frequencies. As a result, a beacon call had to be from a position where it could be heard by either an aircraft or by a satellite that was simultaneously in contact with a ground receiving station. The second problem was pollution of the 121.5/243 channels by inadvertently activated EPIRBS and aircraft emergency location transmitters (ELTs). As a result of these problems and with the widespread use of the newer and directly traceable 406-MHz EPIRBS, the satellite monitoring of the low-frequency beacons has been officially discontinued. Given their proven worth, there is no doubt that a 406 EPIRB belongs on any boat that ventures even a short distance from land.

“Personal” versions of this lifesaving device, heretofore not approved for sale in the United States, should be widely available during the early summer of 2003. Transmissions from these 406-MHz beacons are handled by the same worldwide monitoring system that listens for the larger 406 beacons. Transmission from these personal beacons is at the same five-watt power level as from the larger units; however, the minimum required transmission time is 24 hours at minus 40� (F or C), half that required of the more familiar boat-mounted units. Like the larger beacons, these personal units are waterproof, buoyant and transmit a low-power 121.5-MHz homing signal that is of great value to search-and-rescue aircraft.

In addition to the 406-MHz beacons, approval has recently been granted for a new generation of 121.5-MHz miniature, wearable EPIRB. These low-power, short-range devices are intended to be worn by crewmembers, and in some types, will automatically activate if submerged in water for a brief time. Some incorporate small signal lights or strobes, making them more visible, especially to pilots wearing night-vision goggles. The stability of their 121.5 signal is sufficient for reception by over-flying satellites; however, as noted previously, the satellites cannot store and forward the received 121.5 signal for transfer to a currently out-of-range ground station.

A satellite receiving the signal from the beacon can determine its location to within about 10 nm on the first pass. Many of these personal beacons are used in conjunction with special direction-finding receivers carried onboard the vessel that carries the beacon-equipped crew, thus greatly increasing the chance for a vessel to recover a man overboard in difficult conditions.

Another innovative personal rescue beacon is available in the form of a 121.5-MHz emergency transmitter built into a waterproof wristwatch. Although the power output of the transmitter is on the order of 1/4 watt, the signal is claimed to be strong enough to be received at surface distances up to one nm and up to 15 miles from an SAR aircraft.

Never make a mayday call in jest or in conditions where a routine call for information or later assistance will suffice. However, as captain, it is your responsibility to assure the safety of your passengers, crew and vessel.

A mayday call is clearly in order and should be made without hesitation in the event of: 1) a serious medical emergency, 2) a fire that is not immediately under control (that is, within seconds) or 3) serious flooding of your vessel.

Contributing Editor Chuck Husick is a writer, Ocean Navigator seminar instructor, electrical engineer, pilot and former president of both Cessna Aircraft and Chris Craft boats.

By Ocean Navigator