7-8. Almost every description can be applied to rivers and streams. They may be shallow or deep, slow or fast moving, narrow or wide. Before crossing a river or stream, a good plan will need to be developed. The first step is to look for a high place from which to get a good view of the river or stream. From here, the isolated persons can look for a place to cross.
Rivers and Streams
7-9. Good crossing locations include—
- A level stretch where it breaks into several channels. Two or three narrow channels are usually easier to cross than a wide river.
- A shallow bank or sandbar. If possible, select a point upstream from the bank or sandbar so that the current will carry them to it if they lose their footing.
- A course across the river that leads downstream so that isolated persons will cross the current at about a 45-degree angle.
7-10. The following areas possess potential hazards; avoid them if possible:
- A ledge of rocks that crosses the river. This often indicates dangerous rapids or canyons.
- An estuary of a river, because it is normally wide, has strong currents and is subject to tides. These tides can influence some rivers many miles from their mouths; personnel should go back upstream to an easier crossing site.
- Eddies, which can produce a powerful backward pull downstream of the obstruction causing the eddy and pull personnel under the surface.
Rapids
7-11. To swim across a deep, swift river, swim with the current; do no swim against the current. Try to keep the body horizontal to the water. This will reduce the danger of being pulled under. In fast, shallow rapids, lie on your back, feet pointing downstream, finning your hands alongside your hips. This action will increase buoyancy and help steer away from obstacles. Keep your feet up to avoid getting them caught by rocks.
7-12. In deep rapids, lie on your stomach, head downstream, and angling toward the shore. Watch for obstacles and be careful of backwater eddies and converging currents, as they often contain dangerous swirls. Converging currents occur where new watercourses enter the river or where water has been diverted around large obstacles such as small islands. To ford a swift, treacherous stream, apply the following steps:
- Step 1. Find a strong pole about 3 inches in diameter and 7 to 8 feet long to help ford the stream.
- Step 2. Grasp the pole and plant it firmly on the upstream side to break the current. Plant feet firmly with each step, and move the pole forward a little downstream from its previous position, but still upstream.
- Step 3. With the next step, place foot below the pole. Keep the pole well slanted so that the force of the current keeps the pole against their shoulder. Cross the stream in such a manner that the downstream current is being crossed at a 45-degree angle, (see figure 7-1).
7-13. If there are other people with the isolated person, ensure that they all cross the stream together. Position the heaviest person on the downstream end of the pole and the lightest person on the upstream end (see figure 7-2). In using this method, the upstream person breaks the current, and those below can move with relative ease in the eddy formed by the upstream person. If the upstream person temporarily loses footing, the others can hold steady while the upstream person regains footing. If there are three or more people crossing the stream and a rope is available, the technique shown in figure 7-3 on page 7-6 can be used. The length of the rope must be three times the width of the stream.
Rafts
7-14. Rafts are a useful piece of equipment that enables a safer water crossing when the isolated person is required to cross a large body of water, cross with equipment, or their swimming skills are hindered by injury. If two ponchos are available, construct a brush raft or an Australian poncho raft. Using either of these rafts, equipment can be safely floated across a slow-moving stream or river. The following information will explain how to build field expedient rafts.
Brush Raft
7-15. The brush raft is constructed out of ponchos, fresh green brush, two small saplings, and rope or vine as follows (see figure 7-4 on page 7-7):
- Step 1. Push the hood of each poncho to the inner side and tightly tie off the necks using the drawstrings.
- Step 2. Attach the ropes or vines at the corner and side grommets of each poncho. Make sure they are long enough to cross to and tie with the others attached at the opposite corner or side.
- Step 3. Spread one poncho on the ground with the inner side up. Pile fresh, green brush (no thick branches) on the poncho until the brush stack is about 18 inches high. Pull the drawstring up through the center of the brush stack.
- Step 4. Make an X-frame from two small saplings and place it on top of the brush stack. Tie the X-frame securely in place with the poncho drawstring.
- Step 5. Pile another 18 inches of brush on top of the X-frame, and then compress the brush slightly.
- Step 6. Pull the poncho sides up around the brush and, using the ropes or vines attached to the corner or side grommets, tie them diagonally from corner to corner and from side to side.
- Step 7. Spread the second poncho, inner side up, next to the brush bundle.
- Step 8. Roll the brush bundle onto the second poncho so that the tied side is down. Tie the second poncho around the brush bundle in the same manner as the first poncho was tied around the brush.
- Step 9. Place the raft in the water with the tied side of the second poncho facing up.
Australian Poncho Raft
7-16. The Australian poncho raft is constructed when there is no time to gather brush for a brush raft. This raft, although more waterproof than the poncho brush raft, will only float about 77 pounds of equipment. To construct this raft, use two ponchos, two rucksacks, two 4-foot poles or branches, and ropes, vines, bootlaces, or comparable material as follows (see figure 7-5 on page 7-8):
- Step 1. Push the hood of each poncho to the inner side and tightly tie off the necks using the drawstrings.
- Step 2. Spread one poncho on the ground with the inner side up. Place and center the two 4-foot poles on the poncho about 18 inches apart.
- Step 3. Place rucksacks, packs, or other equipment between the poles. Also, place other items that need to be kept dry between the poles. Snap the poncho sides together.
- Step 4. Use a friend’s help to complete the raft. Hold the snapped portion of the poncho in the air and roll it tightly down to the equipment. Make sure to roll the full width of the poncho.
- Step 5. Twist the ends of the roll to form pigtails in opposite directions. Fold the pigtails over the bundle and tie them securely in place using ropes, bootlaces, or vines.
- Step 6. Spread the second poncho on the ground, inner side up. If more buoyancy is needed, place some fresh green brush on this poncho.
- Step 7. Place the equipment bundle, tied side down, on the center of the second poncho. Wrap the second poncho around the equipment bundle following the same procedure as used for wrapping the equipment in the first poncho.
- Step 8. Tie ropes, bootlaces, vines, or other binding material around the raft about 12 inches from the end of each pigtail. Place and secure weapons on top of the raft.
- Step 9. Tie one end of a rope to an empty canteen and the other end to the raft. This will help to tow the raft.
7-17. When launching any of the above rafts, take care not to puncture or tear it by dragging it on the ground. Before starting to cross a river or stream, let the raft lay on the water a few minutes to ensure that it floats. If the river is too deep to ford, isolated persons should push the raft in front of them while they are swimming. The design of the above rafts does not allow them to carry a person’s full body weight; they should be used as a float to move isolated persons and their equipment safely across a river or stream.
Log Raft
7-18. The log raft is constructed from dry, dead, or standing trees for logs. Spruce trees found in polar and subpolar regions make the best rafts. A simple method for making a raft is to use pressure bars lashed securely at each end of the raft to hold the logs together (see figure 7-6).
Flotation Devices
7-19. If the water is warm enough for swimming and isolated persons do not have the time or materials to construct a poncho-type raft, they can use various flotation devices to negotiate the water obstacle. Items that can be used for flotation devices include—
- Trousers. Knot each trouser leg at the bottom and close the fly. With both hands, grasp the waistband at the sides and swing the trousers in the air to trap air in each leg. Quickly press the sides of the waistband together and hold it underwater so that the air will not escape. Isolated persons now have water wings to keep them afloat as they cross the body of water.
Note. Wet the trousers before inflating to trap the air better; this may need to be done several times when crossing a large body of water.
- Empty containers. Lash together empty gas cans, water jugs, ammunition cans, boxes, or other items that will trap or hold air. Use them as water wings. Use this type of flotation device only in a slow-moving river or stream.
- Plastic bags and ponchos. Fill two or more plastic bags with air and secure them together at the opening. Use a poncho and roll green vegetation tightly inside it to form a roll at least 8 inches in diameter. Tie the ends of the roll securely. This can be worn around the waist or across one shoulder and under the opposite arm.
- Logs. Use a stranded drift log, if one is available, or find a log near the water to use as a float. Test the log before starting to cross. Some tree logs, such as palm, will sink even when the wood is dead. Another method is to tie two logs about 24 inches apart and sit between the logs with their backs against one and their legs over the other (see figure 7-7).
- Cattails. Gather stalks of cattails and tie them in a bundle at least 10 inches in diameter. The many air cells in each stalk cause a stalk to float until it rots. Isolated persons should test the cattail bundle to be sure it will support their weight before trying to cross a body of water.
7-20. There are many other flotation devices that can be devised by using some imagination. Just make sure to test the device before trying to use it.
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