Specific needs depend on the river paddled and local weather

Much of this topic has already been covered above in Emergency Shelter and Survival Kit sections. Boaters always need to strive for the right balance between weight and function. Whitewater kayaks are much smaller these days than 30 years ago so we need to be a bit more selective in what we bring. You can pack much lighter for your typical day trip than longer and more remote overnight expeditions. Often, expeditions will use larger boats like rafts and canoes that can safely store more gear and still run whitewater. Some expeditions cache supplies along the run to cut down on the carrying load. It is always a good practice to select a somewhat easier run when help is very far away - Consider limiting yourself to class III+ instead your normal class IV/V runs. Larger parties can carry more group gear by spreading the load. Always consider the weather when planning a trip. Winter paddling mandates extra clothing, food, and perhaps a temporary shelter. Summer paddling requires extra water to avoid dehydration. Always think "What If?".

Food, water, extra clothing, shelter, fire making supplies, …

Trust your gut, if there's any chance of any overnight stay if an incident takes place - be prepared.  Carrying extra high energy foods doesn't take up much weight or space.  These snacks also mitigate a second issue - low blood sugar and hypothermia.  Extra clothing is a wise precaution.  When someone takes a bad swim, getting them in dry clothes pays huge dividends.  Extra thermal gear like an NRS hood is a great precaution (I carry one in my PFD vest).  I also carry Glacier Gloves in my pin kit.  These are often loaned out when someone has cold hands or forgot their pogies.  A Tyvek tarp weighs practically nothing and has all sorts of first aid and shelter uses.  Heck, getting out of the wind for a spell can be real nice.  Packing some waterproof matches can be beneficial and they are a part of many repair kits.  Extra water is certainly smart any time of the year.

Survival Kit

Lets picture the scenario where someone is injured and you need to wait for professional help. Another possibility is running out of daylight and it is no longer safe to proceed. In either of these cases, you might have to spend an unplanned night on the river. To handle this scenario, you need to handle the basics:

• Food & Water
• Clothing
• Shelter

It is always a good idea to carry some extra food like energy bars and other high energy food like trail mix and dry noodle mix. You should also have water proof matches or some other fire starter. Some carry a Jet Boil (described below). These items are quite useful for preventing or treating mild hypothermia. Water is a bit more complicated - we need a lot of water to stay hydrated. Although we may carry an extra bottle in the boat, this will not cut it for an overnight stay. Consider adding some water purification tablets to your survival kit (or first aid kit).

You will also need a change of clothes or at least extra layers to stay overnight. Many pack extra clothes in a dry storage bag. Once again, this has a dual purpose as it may help someone with mild hypothermia. I strongly recommend packing a few lawn/leaf plastic bags. They make a great improvised rain suit and take up hardly any extra space.

You will also need to set-up some type of shelter to escape the elements. A tube tent and a space blanket are really cheap, provide adequate protection, and are quick to set up - see below. The lawn/leaf bag can also make a great bivy sack as well.

Simple repair kits containing sewing thread, sewing needle, safety pins, safety razor, duct tape, and a wine cork (to replace a lost drain plug) are quite easy to carry. Also consider packing a small flashlight.

The above items can easily be added to a first aid kit. Alternatively, you can purchase a specially made commercial survival kit for $34: Survival Kits.

Hauling Line

In general, kayakers don't need a special hauling line. Get a really good full size throw rope instead. On the other hand, raft supported expeditions may benefit from a 100' or longer low stretch HTP Polyester or Dyneema line - see: Hauling Line.

Communications

Some items of communications gear are the safety whistle, mirror, and cell phone. Cell phone coverage is rapidly improving these days, many rivers outside of West Virginia have decent coverage. Verizon provides pretty decent service on most West Virginia runs as well - even on the Lower Big Sandy which surprised me. Sometimes you can boost signal strength simply by climbing up the hill a bit. You will need to store in a waterproof container like a Shredready Dry Bag or Pelican Box. The cell phone can be a very valuable safety device.

Breakdown Paddle

On lengthy boating trips, it really makes a great deal of sense for someone in your group to carry a breakdown paddle. Paddles break, get lost, or get stuck in rocks where they can't be retrieved. On shorter trips, I like to pack hand paddles in my boat as a backup.
Cost varies between $100 - $300 depending on quality.
Werner Breakdown Paddle.

Pin Kit

This is an optional piece of gear that you may wish to consider on expedition trips with raft support. On typical trips, I highly recommend that each paddler carry the following:

2 carabineers, always locking
Throw rope
1 20' 1" nylon webbing strap
2 prusik lines with knots already tied

A pulley or two is a good idea as well to minimize friction in mechanical advantage systems. Nearly all kayak pins can be extracted with the list of equipment above. If the kayak has air bags, usually a simple tug with rope on the boat pulling it back out from the direction it got pinned will suffice.

For the group pin kit, a great rule of thumb is 4-3-2-1:

4 locking carabineers
3 pulleys
2 prusik loops
1 30' webbing and a 75' hauling line like Dyneema/Spectra

Premade kits like these from NRS are more costly:

NRS Kayak Un-pin Kit Cost: $185
NRS Z-Drag Kit Cost: $245

Emergency Shelter

The best laid plans go astray sometimes. Imagine a very late put-in, add a few swims and a recovery, and before you know it - you ran out of daylight. This can be a very serious situation if you are not prepared to spend the night. It makes a great deal of sense to pack a lightweight tube tent and an emergency space blanket in a few boats:

Tube Tent: Cost: $4 - $6
Space Blanket: Cost: $1.35

Jet Boil

Nothing beats a warm beverage when you are really chilly, on or off the river. It is hard to beat a Jet Boil for tasks like this.
Jet Boil Cost: $100

Specific needs depend on the river paddled and local weather

We need to apply judgment in selection of group gear for each trip.  If I'm paddling easier venues on larger rivers, I typically skip the pin kit for instance.  Over night gear is highly recommended for trips that take all day and Winter paddling of course.  As a geneeral rule, my minimum group gear is:

• First Aid Kit
• Everyone carries a Throw Rope and a couple of carabiners.  
• A breakdown paddle for more advanced trips
• Usually a cell phone
• Some sort of repair kit

This is an alternate first aid kit that passed the scrutiny of two EMT’s (Thanks to Jay B, MCC Club).

• 1 - First Aid Book
• 1 - Box Plastic Adhesive Bandages - 1” x 3” 16/Box
• 1 - Tweezers
• 1 - Scissors
• 1 - Spool Tape - 1/2” x 5 yards
• 2 - Compress Bandage - 3” x 3”
• 1 - Triangular Bandage - 40”
• 1 - Small Ice Pack
• 1 - Box Fingertip Bandage - 10/Box
• 1 - Box Cloth Knuckle Bandage
• 1 - Eye Dressing
• 1 - Box Telfa Pads - 1 1/2” x 2” 12/Box
• 1 - Roller Gauze
• 3 - Packages Clean Wipes
• 1 - Compact CPR Shield
• 1 - Latex Gloves, Pair
• 1 - Finger Splint
• 1 - Cell phone w extra charged battery
• 1 - matches
• headache remedies
• insect bite kit
• ammonia inhalant ampoule sticks
• space blanket
• energy bars