Doing a hand roll

A hand roll is an eskimo roll without a paddle, which in turn is a technique to get your kayak upright.
This guide focuses on hand rolling instead of a normal eskimo roll because in canoe polo the odds are high you will be pushed over when holding a ball and losing grip on your paddle.

2 hands, no ball

The first step in hand rolling is to get your body as close to the surface as possible. The easiest way to accomplish this with a hand roll is to tilt to the back, and pick a side. Your face will be looking at the bottom when upside down.

Stretch out to the side as far as possible and start the roll with one hand (the one closest to the surface).
Start the same hip movement as with a normal roll and follow up with your second hand. Both hands should be pushed downward and once the first hand is losing its effectiveness you can start the second hand & flip your body over the kayak and move forward.

1 hand, 1 ball

If you are holding a ball while being pushed over, you can replace any of the hands by the ball. The easiest method is to hold the ball in your first hand. Use the ball as a floating device an pull on it to start the roll. The second hand is used like normal.

If your opponent is still in the area, make sure you hold the ball firmly, preferably in the hand furthest away from him.

Demonstration

This YouTubu video show a normal roll, then a hand roll and finally a hand roll with the ball.