Intro to Sea Survival | Life Rafts | Provisioning
The following signaling devices may vary from one manufacturer to another. Each manufacturer will provide its own operating instructions, which should be adhered to.
Fig. 3-3: The above diagram illustrates the height at which various
types of signal flares will be visible.
Pyrotechnics
Orange Smoke Flares. These flares are designed for daytime use and provide one of the best signals for locating. They are hand-held, and have a burn time of about 50 to 90 seconds, depending upon the model. Some are equipped with wooden handles, are waterproof, and have flotation capabilities.
Red or Bright-White Flares. These are primarily for nighttime use. At night a smoke flare would be virtually invisible. These handheld devices have a candlepower of about 500 and an approximate burn time of 2 minutes.
Highway Flares. These produce a red light and have a lengthy burn time. They are much less expensive than the regular marine flares, but they produce a considerably smaller amount of light (approximately 70 candle power). These flares are not Coast Guard approved, and one disadvantage is that they produce a hot sulfur ash that can be a hazard.
Aerial Flares
Handheld Rocket Flares. These are generally of two types: low altitude with a short burn span, and high altitude with a long burn span.
Pen Gun Flares. A 45-caliber cartridge is screwed into the end of the pen gun and fired by a spring-loaded pin. The flare generates a candle power of 4000, and attains altitudes of 450 to 500 feet.
Pistol Launched Flares. These are generally avail able In 12 gauge, 25mm, and 37mm. They produce a candlepower of 10,000. They are also referred to as meteor flares, and are capable of alerting distant ships from as far away as 20 miles and aircraft at around 10 miles, depending on atmospheric conditions. A parachute equipped rocket flare that is capable of reaching altitudes of 1,000 feet can have a burn time of 60 seconds or longer ( Fig. 3-4).
Fig. 3-4: An alert/locate
device: Flare Gun.
Note: Rocket flares capable of reaching even greater heights with longer burn times are available, but are more costly.
Colored Dye Markers
Colored dye markers are used primarily as a locating device. The powdered dye is dispersed on the ocean surface around the raft. The marker is usually bright orange and can be detected from as far away as 10 miles by aircraft on a clear day. Because it remains on the surface of the ocean for a period of time, it’s more noticeable from the air than from other craft at sea level, and will last longest in smooth seas.
Heliograph (Mirrors)
The reflection of a mirror or shiny object is very noticeable on the ocean, and the fact that it’s reusable increases its value as a signaling device. The mirror should have a sighting hole in the middle and reflection capabilities on both sides, for maximum efficiency and to allow for proper aim on the target.
Flags or Panels
Flags or panels that are brightly colored are used for both alert and locate purposes. They emphasize a contrast to the ocean’s background (a bright orange life raft canopy would accomplish this even more effectively.) The distress panel, although it takes up more space than the flag, is less influenced by the wind (or lack of it), and is also reflective under a search light.
Strobe Light
A strobe light is a high intensity flashing light. It can be used for both alert and locating purposes. The blue/ white light flashes about once every second. These water proof units are small in weight and size, and can be easily attached to gear or person. Most are equipped with off/on switches (gravity activated or water activated).
Whistle
A whistle is an extremely effective locator signal for man-overboard situations. If you’ve fallen overboard, your voice may be virtually useless as a signaling device, especially in conditions of rough weather or fog. A whistle attached to your PFD (and Man-Over-Board Pole) will dramatically increase your chances of being heard and located. It’s best to use a plastic whistle that won’t corrode.
PREV: All About Signals (intro)
NEXT:
Radio and Telegraph Devices • Using Distress Signals • Signaling Device Limitations
• Signal Provisions • Maintenance and Storage • Mayday Procedures • Signaling
Skills • Use Your Signals Wisely
All Articles