The hand roll is a great move to master for a number of reasons. Most importantly, it's a confidence booster. Whitewater kayaking is as much about confidence as it is about skill.
Hand rolling is a method of righting a capsized kayak without using a paddle, but using the floatation of your upper body along with resistance from your hands and arms to allow a strong hip flick and delicate body positioning, returning your body weight to the kayak's centreline quickly by throwing an arm or sweeping your torso.
While there is an outside chance you might need to use this roll someday,
the main benefit is to improve the technique and reliability of your paddle roll.
It requires a solid rolling technique and an effective hip flick.
Once you learn the hand roll, you might even find that it becomes your preferred roll. It may be quicker to set-up underwater without the paddle if you know you can get up just as reliably using your hand roll. Of course this may leave you without paddle in the middle of a rapid, but for calmer water it might make sense.
The hand roll is a great skill to practice in an indoor pool during the winter months. Once you've mastered it then in the summer you can leave your paddle on shore at times and practice cool new things that will dramatically improve your overall paddling. Try some eddy turns and quick S-turns on a clean eddy line, or try surfing and spinning in small holes.
You'll become more aware of your body's position over your kayak
and how to let the river do more of the work for you,
which will ultimately open the door to the moves you've only dreamed about.
Wear clothing that does not get in the way underwater when you capsize. A short sleeve top may be better for initial training, because a long sleeve anorak or hoodie can hold a lot of water in the sleeves.
Later on when you wear a long sleeve hooded cag, tie the hood around your neck or put it up so it fits well. Make sure you can see even when you turn your head.
To prevent water from getting up your nose, you may prefer to wear a nose clip. Without a nose clip you will soon discover that breathing out slowly through your nose will prevent the water from going in.
It helps to gradually reduce the size of the paddle while practising,
ending up with a ping-pong paddle or webbed glove,
until finally you are able to roll back upright holding nothing but water and a giant sized grin.
First, the hand roll is misnamed. It should be called the leg roll, because, as in any well-executed roll, it is the legs that accomplish most of the work. In most hand rolls, the upper body, including the hand or hands, substitutes for the paddle that serves as a support.
You press the thigh of your lower leg upward against the thigh brace
and push with your upper foot on the foot peg,
an action which twists the boat virtually upright.
This leg pressure is generally termed the "hip-flick", another misnomer,
because it does not need to be applied quickly all at once, although it may be.
A good drill to learn the hip flick is to lean over and put your hands on the edge of a swimming pool or another boat. Lean over until your head touches the water. Remember to use a spray deck or you sink the boat.
Practice flexing (flicking) your hips from one side to the other, so that your boat flips from an upright position to an upside down position. It's all in the hips, but this is not a natural body movement, so you have to practice it.
Now lean back or forward onto the deck of the boat and do it again. This should be easier as you're closer to the axis of rotation, and thus need less leverage.
The capsize is the same no matter which way you choose to come back up. It a real capsize you may not have time to set up your roll. So get with it and train for any eventuality.
Roll towards the side of your choice. Wait until you are upside down. Get your bearings.
Lean back onto the deck of your boat, look up towards the water surface. Reach with your hands towards the surface, palms down, away from your boat. Use like a paddle to get up. Push hard downwards or in a sweeping move until your upper shoulder comes out of the water.
Keep your head in the water, leaning right back on the deck. Pull your lower knee up and use your hip to flick the boat upright. Throw the upper arm out over the top of the boat. It acts as a counter weight and helps you turn upright.
Stretch your lower arm and use it in a downward slapping motion to finish the roll.
Don't lift your head too early out. That adds to the weight you want to shift. Keep your head in the water, it should come out last.
Too much heavy clothing when you begin.
Start with just jeans and a t-shirt or short sleeve canoeing cag to avoid chafing of the boat or spray deck.
When you get better, try more kit.