You're in charge of taking care of yourself while on the river. We're talking about prevention of injury, big and small. Let's start on the small side: cracked skin, rashes, and sunburn. The wilderness is tough on city dwellers' skin. Then we'll cover a few points on the life and death end of the scale.
I used to think it was just me; maybe something was different about my skin that caused my fingers to crack and peal after a week on river. Then I learned through postings on Internet forums that this was a more common problem. The river environment is hard on your skin and I wasn't taking proper care of myself.
Your hands and feet are constantly alternating between wet and dry. Your sandal straps are full of silt which abrades your feet. You're using bleach in your dish water and wash your hands using alcohol based waterless hand sanitizer. So your hands and feet take a beating, and if you don't take precautions, your skin will develop cracks which can be very painful. Here are a few things the rafting community has to say on the subject of skin care and first aid for skin cracking.
"Cornhusker's Lotion kept my hands and feet in shape - no problems." "Gold Bond Medicated Powder is great for any heat related rash problems." "Start applying lotion 2 weeks before your launch date. My last trip was a 21 days and my hands were as soft as a babies bottom at take out."
"I've taken to using "Mom's Stuff", which is made and sold by Lee Bennion, wife of Grand Canyon guide Joe Bennion (AKA Joe the Potter). Joe himself would be too much a gentleman to post about it. But it's really great stuff, and leaves you with the gentle hint of a pine forest as it works its magic. (Geez, I bet I could write ad copy, coming up with language like that....)
I saw this great advice awhile back: "Put a tube of Tinactin (or any other anti-fungal) in the first aid kit. I was advised by a sage Grand Canyon boatman that the dreaded "paddle boat butt" is not a wet short rash, but usually due to a fungal infection. The nearly instant relieve provided to the member of your party who is walking bowlegged around camp and may be miserable for the rest of the trip is well worth having it along."
Also bring along some liquid bandage products such as New Skin to keep small cracks from spreading and to protect open cracks from silt, grit, and sand.
You can effectively treat abrasions from sandal straps (referred to as "Chaco bites") by covering the abused spot with a liberal strip of water proof rubber first aid tape. Apply the protective tape at the very first sign of abrasion as any small wound to the feet will just get worse over the course of a river trip.
No matter what your skin type, you cannot have too much SPF 50 on a river trip. Also, be sure to bring a wide brim hat, long sleeve shirt, and maybe a bandana to cover the back of your neck. Make sure you apply sun block to the back of hands; tops of the feet, and tops of your knees as these surfaces are constantly exposed when you're sitting in the raft. It's amazing how tan these spots get, even when they spend the week slathered in SPF 50! Consider a zinc oxide product for these areas too; they will likely catch the sun at the most direct angles. Remember to apply sun screen early and often.
Finally, before moving on to more life and death subjects, remember that living out in the sun all day can dehydrate you. Ironically, your body may attempt to counteract dehydration by storing water. So keep hydrated to reduce swelling.
There are several good books river rescue, wilderness first aid, and managing emergency situations. So I won't cover those topics here. Instead I'll state the obvious: carry a good first aid kit and the necessary safety and rescue equipment and know how to use it. That said; let's concentrate on some common-sense stuff to put the odds of staying safe in your favor. Disclaimer: the following are just my opinions and things that we do on our trips. Take any of this stuff as advice at your own risk.
I'm amazed at guides and veteran river runners who choose to not wear their PFD ('personal floatation device', aka 'life jacket') while on the river. Shit happens. I particularly remember reading about their drowning. Don't be caught dead without your PFD. Not only will you be dead, but your stupidity will be the topic of discussion around the Internet for quite awhile.
Entrapment is the term for catching or entangling a part of your body in something that prevents you from being able to swim or hold your head above water. Next to falling into the river without a PFD, or getting banged on the head during a flip, entrapment is probably the biggest danger you face on the river. Stories abound about entrapment hazards where folks fall overboard and yet catch a hand or foot in a loose coil or loop on their way overboard. (I need to mention that a fourth major threat to life is hypothermia due to cold water if you're thrown out of the boat and not quickly recovered.)
River rafting involves lots of ropes and straps. We take great care to ensure that a rope does not inadvertently become attached to a person, preventing them from moving or escaping, and getting dragged by the river current. Because of entrapment hazard, it's vital to keep a tight ship. Never leave loose rope coils or straps lying around on a boat, where a foot or hand could become entangled. Also, cargo nets are a danger if the openings are large enough to catch a hand or foot.
Don't tie knots or loops in the end of ropes, lest the knot fall overboard and become caught between rocks or another stationary object, thus anchoring the rope. A rope overboard with a knot in it can hang up immediately between rocks and stop your boat in its tracks. If that rope happens to get wrapped around an ankle before catching on the rocks, you have an instant emergency. No joke, it's Murphy's Law. We like to keep bow and stern lines in mesh bags. Load the bags like you load a throw bag. Rope will be immediately available without tangling and the entrapment hazard is curtailed.
Inspect your boat regularly. Strive for a compact load. Anything sharp that protrudes from your load is bad news as raft passengers can get tossed around in rough water and land on sharp corners, points, or edges.
And while near a river, don't tie a rope to a live human being. When climbing a mountain, participants rope themselves together when they move on the mountain so that if one falls, the others can arrest the falling climber, and prevent their injury or death. In a river environment the environment is doing the moving. A participant in rafting is in grave danger if they're anchored in the river while the current presses against them. So we never tie a rope to a live human being. The only exception I can think of is a what they call a 'live bait' rescue in which the rescuer has a special quick-release harness; I'll leave the explanation of such techniques to the book authors.
I think the ability to self-rescue should determine the minimum age for kids allowed on a river rafting trip. If you're considering bringing young children on a river trip, go out and swim a rapid yourself before you make your decision. Even a little class I or II rapid will do the trick. It doesn't take much to gain a whole new appreciation. One gulp of cold water 'down the wrong pipe" will give you the proper perspective. Shit happens; people get tossed out of the boat at the most surprising and inopportune times. If they can't take care of themselves once they're in the water, they don't belong on the river. Just my opinion.
Talk with your group about safety and safe practices before the trip begins. River rookies may be surprised to know that veteran white water river runners talk about safety every day, before they pull away from camp. They use daily meetings to remind each other about hand and whistle signals, and decide which boats will run first and last, and discuss difficult sections that will be encountered that day. Plan the day. Plan to stay safe.
Keep knives at the ready. River runners wear knives on their PFDs to cut away entrapments. Hopefully these knives are never needed for this purpose and are only used for spreading peanut butter or cream cheese. The idea is that if someone becomes entrapped, the knife is ready to draw to cut the person loose. If you're going to carry a knife on your PFD then practice removing it. Get in the habit of pulling out the knife to make sure you know which edge is the sharp one when you pull it out in an emergency. In a real emergency, there may not be time to figure that out.
White water rafting is a thinking sport and you can avoid most problems by staying alert and carefully considering all your options when bad things start to happen. Many river accidents can be traced to a series of bad decisions, not just one. Frequently, changing just one of those to a good decision will derail the catastrophic chain of events. In other words, you often get a couple chances to make things better or worse. Choose carefully.
While you're on a river you cannot let down your guard. On the river and in camp, you must continually be alert to what's happening around you and be anticipating what might happen next. No horsing around. Keep kids from acting mindlessly, chasing each other all around camp. Forms of play that may be considered safe in town are in fact dangerous and that danger is amplified when there is no 911 to call. Always watch your step and watch for snakes. In the sport of whitewater rafting, your knowledge and your attention keep you safe. You can't know too much, have too much experience, or be too attentive.
Another form of entrapment is possible if you're tossed out of the boat. A foot extended down can get caught in a 'V' of rocks on the river bottom, or your body can get pressed into a tangle of tree limbs or brush. Any situation where water can flow through an obstruction but your body cannot is a disaster waiting to happen. Like a colander for spaghetti noodles, these situations are referred to as 'strainers'. Learn the swimming techniques for avoiding and dealing with such hazards. Learn how to bide your time to grab a breath in the rapids, and keep your face pointed away from breaking waves. Ask questions of veteran rafters. We keep in practice by swimming small rapids with a boat close at hand.
Throw bags are a double edged sword. They can be the perfect tool to aid in an emergency and yet they can amplify the hazard by risking entangling, or further entangling the victim. Everyone on a rafting trip should know how to toss a throw bag and practice using it. But when the need to throw one arises, be careful. Make sure the best person readily available is doing the throwing. Warn the 'swimmer' that the rope bag is being thrown, lest they don't notice.
Practice throwing the bag and do so in as realistic a manner as you can. You can practice by having someone at 40 to 50 feet away from you walk or trot (or swim) by as you try to lay the rope out in front of them. Have the person grab the rope and keep going. Once they grab it, you'll quickly see that you must brace yourself to take the weight as the 'current' pulls them away. Learn the proper way to re-throw a deployed bag, and learn the correct way to stuff the rope back into the bag for storage. Wet bags are heavier and the rope feeds out of them faster, so practice with a wet bag as well as a dry bag.
Be sure to take a throw bag with you when you scout or go below a rapid to take pictures. Hopefully you won't ever need it, but when you do, you do.