Survival Technology

One of the classic stories of survival at sea is Steve Callahan’s account of his 76 days adrift in the Atlantic Ocean in 1982 after his boat was holed in the middle of the night by what he believes was a whale. There are, of course, other survival stories, some even longer than 76 days, but what makes Callahan’s story of particular interest is Callahan himself. Yacht designer, builder and experienced sailor, he was well qualified to participate in the grueling Mini-Transat Race. He had a good, well-found vessel thoroughly prepared for its upcoming voyage. Yet he ended up setting a record for the longest solo survival in an inflatable raft.

The problem of abandoning a vessel in mid-ocean can be considered in two parts – survival and rescue. The survival part begins with the life raft, and that is a subject unto itself. There is much to be said about the selection of a life raft, most of which was thoroughly covered in an excellent and comprehensive article by Steve D’Antonio (“Life-Raft Essentials,” May/June 2003, Issue No. 130) and is recommended reading. However, the raft, critically important though it is, can only provide you with some shelter, a measure of warmth and a not-so-firm foundation from which you can see to your survival – and rescue – needs, if you have provided for them.

If you are to survive, you must be prepared to deal with three specific threats: 1) hypothermia, 2) hunger and 3) dehydration. Callahan had done all that could be done in terms of survival. He had a quality, state-of-the-art oversized raft that was well equipped: spear gun, fishing kit, water bottle, sheath knife, air pump, space blanket, etc., including a state-of-the-art EPIRB. He had added to these provisions two duffel bags, one filled with clothing, blankets and other things necessary to deal with hypothermia, and one with food. He also had 10 gallons of fresh water stowed up in the forepeak to forestall problems of dehydration. However, as the weather and the fates determined, he was unable to retrieve these supplies before his vessel was lost and he spent two-and-half months adrift.

Prepackaged water and foods have not changed all that much in the past 20 years or so. The foods taste better and there’s a wider selection of more nourishing food products available, e.g., the military’s Meals, Ready-to-Eat (MREs) and the highly concentrated “survival” products. The availability of space blankets is another improvement, but the major advance in survival technologies has been in watermakers.

Making water

If the importance of a nutrient to the human body is determined by how long a person can do without it, water has to rank No. 1. We can survive without food for weeks or even months; without water, we can die within eight to 10 days. The body must take in at least 18 ounces of water every day to be able to function at a basic level. It’s clear that water is our first priority. The question is how best to make it.

Solar stills: The oldest emergency water-making technology is the solar still, which can take various forms, but for the mariner adrift is in the form of an inflatable balloon. Technologically, they are very simple: solar radiation causes seawater in the main chamber to evaporate, condense on the inner surface of the balloon and run down into a separate collection chamber in the bottom of the balloon assembly. A solar still can produce one to four pints (16 to 64 oz) of fresh water a day. These devices are effective, easy to store and inexpensive (about $200). However, they are slow and their output is unreliable since you cannot predict the weather and they need sunshine to work well. Also, they are somewhat fragile. Callahan had three of these on his raft; one developed a leak, one got punctured and he managed to keep one functioning with parts from the other two.

Manual reverse osmosis pumps: One of the more significant innovations of the last 20 years is the hand-operated reverse osmosis pump, considered by many the only practical and reliable way to make potable water aboard a life raft. Bill Butler, who, with his wife Simone, drifted for 66 days in 1989, credits the Katadyn Survivor 35 with being the thing that saved them. The Survivor 35 can produce 1.2 gallons per hour (153.6 oz) at a pumping rate of 30 strokes per minute, weighs 7 pounds, measures 5.5 inches wide by 22 inches long by 3.5 feet high and costs between $1,500 and $1,900. There is a smaller version, the Survivor 06, that produces 36 oz per hour (0.28 gallons) at a rate of 40 strokes per minute. It weighs only 2.5 pounds, measures 2.5 inches wide by 8 inches long by 5 inches high and costs $560 to $800, depending on where you shop. According to Alan Lizee, president of Katadyn North America, “They are easy for anyone to pump. The S-06 is smaller and less expensive, but takes more effort to make water. But you are alive. The S-35 is larger and makes water very easily. It’s easy to make as much water as required. Either should be mandatory in any well-equipped ditch kit or life raft.”

Forward osmosis emergency desalinator: The most recent innovation in survival technologies was introduced to the commercial market at the Annapolis Sailboat Show in October 2006. The SeaPack Emergency Desalinator by Manta Ventures LLC, while new to the commercial marine market, has been in use by NASA and the U.S. military for several years with ground forces in the Middle East and as standard equipment on the C-130 aircraft. SeaPack is an emergency desalination system that converts seawater into potable fresh water without electrical energy or manual pumping. It works on the basis of forward osmosis.

Forward osmosis filtration uses an osmotic agent to create osmotic pressure and draw the water molecules through a semi-permeable membrane filter. SeaPack uses proprietary syrup similar to sport-drink syrup but especially formulated to meet government requirements as the osmotic agent. This syrup maximizes filtration capabilities and enhances both its combination with the water and the preservation of the resulting drinking water. A SeaPack unit weighs 2.75 pounds and measures 9 inches wide by 16 inches long by 2 inches high in a soft, pliable package. It will produce 17 ounces of water (using one sugar charge – the unit comes with five charges and more can be purchased) in five hours at 68° F (32.2° C) without agitation. Warmer water and agitation allow water to move more easily through the membrane and speed up the process. Each unit has a suggested retail price of $120.

What makes this technology attractive is that it requires no electrical or mechanical power, does not require sunshine, requires no maintenance, is easily stored and produces a high purity, pleasant tasting and high-calorie drink.

With only an inflatable solar still, Callahan survived for 76 days and, truth to tell, none of the above advances in technology would have shortened his ordeal. The deficiency was in the area of the rescue systems available at the time. Survival is, of course, the goal, but what is really wanted is rescue as quickly as possible. So much has changed since those times, 25 to 30 years ago, which, while it may not have made his ordeal any more enjoyable, may have shortened it considerably.

The rescue portion of the abandoned vessel situation boils down to the one objective of shortening the time adrift. Rescue systems can be divided into two parts: communications and navigation.

Rescue systems

EPIRBs/PLBs: The early emergency position indicating radio beacons (EPIRBs), such as the one carried by Callahan, were class A (automatically activated) or B (manual activation) radio transmitters, which operated on 121.5 and 243 MHz and were designed to be detected by overflying commercial and military aircraft. Unless the abandonment occurred on a heavily traveled commercial air route, the chances of detection were not very good. Satellites were later designed to detect these EPIRBs, but were not very effective since the satellite had to be in line of sight of both the EPIRB and a ground terminal in order for detection to take place and rescue forces alerted. The EPIRB signal had to be picked up by a satellite receiver while it was being broadcast, (sort of like telephone calls before we had answering machines) and since battery life was only sufficient for 72 hours of operation the chances of detection were slim indeed. Callahan’s EPIRB died before he was detected.

In 1979, the United States, Canada, France and the Soviet Union established the Cospas-Sarsat (COSPAS is a Russian acronym, which loosely translates into “space system for the search of vessels in distress;” SARSAT stands for “search and rescue satellite aided tracking”) international satellite-based search and rescue system. These four countries jointly developed a 406 MHz satellite EPIRB as a key element of the Global Maritime Distress Safety System (GMDSS).

GMDSS provides worldwide satellite coverage even in the most remote areas. When a satellite detects a distress signal it immediately relays the detected signal to ground stations called local user terminals (LUTs), located all over the world. If no LUT is immediately in range, the satellite stores the message and sends it to the next LUT to come into range. The LUT then forwards the received signal to a marine rescue coordination control center (MRCC), where computers automatically analyze the message to identify the transmitting EPIRB through its registered identification number, verify its authenticity and calculate its location.

The MRCC then notifies the rescue control center (RCC) that is responsible for the area in which the incident occurred, e.g., the Coast Guard, Civil Air Patrol or a foreign country’s military, so the RCC can launch a search and rescue effort. With non-GPS enabled EPIRBs, the MCC analyzes the signal’s Doppler shift to determine the EPIRB’s location to within one to three miles (3.2 to 4.8 km). With the more recent GPS-enabled EPIRBs, position can be determined within 328 feet (100 m). Today, a 406 MHz can be detected and located within a few hours of activation, even in remote areas.

A PLB (personal locator beacon) is a portable unit that operates much the same as an EPIRB. They are designed to be carried by an individual. Like a 406 MHz EPIRB, they operate on 406 MHz and include a low-power 121.5 MHz homing beacon. They are generally less expensive by a couple of hundred dollars. They are available both with integral GPS and with a GPS interface capability. However, they can only be activated manually. A PLB makes an attractive option for the ditch or “bye-bye” bag.

Both of these devices are fast – a bit more than one minute to achieve a GPS fix and just about three minutes to transmit a position signal. The average time to notification of RCCs via 406 MHz EPIRB/PLBs is one hour worldwide. International rescue operations require communicating across language barriers and agency limitations, and may take longer.

Thus, the 406 MHz EPIRB with integral GPS is my nomination for the single most important piece of survival/rescue equipment to come along in the last 25 years.

Satellite phones: The satellite-based phone is another critically important development in the last 25 years. The Iridium system, operational since 2001, is a satellite-based personal communications network that provides voice communications from virtually anywhere to anywhere on Earth. With a constellation of 66 satellites cross-linked to each other, the system is the first truly worldwide telephone service. Iridium provides complete coverage of the earth including oceans and Polar regions, where no other form of communication is available. Calls are relayed from one satellite to another until they reach the satellite above the destination subscriber unit, then the message is relayed back to earth. The large satellite constellation ensures that every region on the globe is covered by at least one satellite at all times. With Iridium satellite phone service and a handheld GPS, a survivor is no longer solely dependent on his EPIRB or on the possibility of a passing vessel. It would be well for passagemakers to identify the MCCs and/or RCCs in the areas in which they will be cruising and include that information in the ditch bag.

Iridium does not sell directly; products and services are available through some 42 service partners throughout the world, 12 in the U.S. alone. Purchase and rental plans vary widely and you’ll have to do some comparative shopping, but it will be well worth the effort.

Digital selective calling (DSC): A DSC handheld VHF radio is, along with an EPIRB/PLB, a satellite phone and a handheld GPS, right up there at the top of the list of “don’t leave the boat without it” survival devices. Digital selective calling (DSC) is basically a paging system that is used to automate the process of sending distress alerts over VHF marine radio systems. Operating a DSC radio is the same as operating one without DSC except for the calling function, which is a digital signal sent on channel 70.

When used to transmit a distress alert, you simply lift the cover on the “red button,” select the nature of your distress from a list on the screen, then press and hold the red button down for five seconds. This will activate all of the radios on all the vessels within range, an area somewhere between 45 and 65 square miles or more, depending on how high you can get the antenna. The distress message will include, as a minimum, the identification of the one who registered the radio as well as the radio’s position if connected to a GPS and may also include the nature of the distress. Since DSC-capable VHF radios must be carried on all passenger ships and most other ships of 300 tons or more, and are carried on numerous smaller vessels not subject to the SOLAS treaty but regulated by national authorities including most fishing vessels, a DSC/VHF greatly increases the chances of a rescue. Also, a VHF radio may be more successful in alerting a passing vessel to your plight than a flare. Handheld DSC/VHFs are available for about $200.

Search and rescue transponders (SARTs): Radar transponders you can take into a life raft, SARTs are used to assist in the location of survival craft or distressed vessels. These are compact 12.5-inch-by-3-inch units weighing between 0.75 and 1.5 pounds.

When the device is turned on, it automatically goes through a short test mode and after about one second, it goes into the receive mode and remains there until it detects a radar pulse. Upon receiving an interrogating pulse from X-band marine radar, it switches to a reply (or transmit) mode and sends a series of pulses. These pulses appear on the screen of the interrogating radar as a series of 12 bright dots, the first of which shows the location of the SART. This radar data leads the rescue vessel directly to the SART. While the unit is in the transmit mode, indicator lights and an audible buzzer are activated to alert the survivor to the fact that the SART is being interrogated. When the radar signal stops, the SART returns to the receive mode.

With a fully-charged battery, a SART can operate in the receive mode for a minimum of 96 hours, after which it will still respond to radar signals for an additional eight hours. The detection range depends upon the height of the ship’s radar mast and the height of the SART, and is typically between five and seven miles or so. These devices aren’t cheap, with prices in the $1,200 to $1,600 range, but are found at discount marine stores for $800 to $1,000.

Laser flares: It’s a familiar story: a survivor uses up his flares the first time he sees a freighter way off, hull down on the horizon, and later, when a ship passes closer up, he has none left. I don’t know who said it first, but “flares are like blessings, you can’t have too many.” However, if you were to pack all the different types of flares in the quantities recommended, you wouldn’t have much room for anything else on the raft. There is a recent addition to the flare family that deserves a place in the raft.

The Greatland Laser Rescue Flare is a small, black tubular device, 4.5 inches long by one-half inch in diameter weighing a mere 4 oz. It’s powered by a small 6-volt lithium battery and is conservatively rated for up to five hours of continuous operation with a range of up to 10 miles (16 km).

The basic concept is to modify the laser light to project a thin, vertical fan-shaped beam. The thought being that such a beam would be much more easily seen if properly used by scanning the target or the horizon. The cost is about $100.

RescueStreamers: Not a “high tech” device, but a good idea nonetheless, the RescueStreamer product has an interesting genesis. A geochemist, inspired by contemporary artist Christo’s pink plastic wrapping of the islands in Biscayne Bay, spent 11 years in R&D, and finally introduced the RescueStreamer in 1994.

This is an 11-inch-wide-by-40-foot-long (28 cm x 12m) plastic ribbon weighing 13.5 oz (383 g) and costing $55, which streams out behind a life raft.

So, like flares, and blessings, the more devices you can have on the raft, the better your chances for both survival and an early rescue, and that’s a good thing. It may be a bit cramped, but your stay will likely be shorter!

Ev Collier is a freelance writer who lives in Lynnfield, Mass.

By Ocean Navigator