When paddling on a river, verbal communication is not always possible. Therefore people worked out hand, paddle and whistle signals.

During my research I had to conclude that these signals have not been standardized. Not even the basic signals. Therefore I decide to follow the basic signals by American Whitewater and extend them with a few other, commonly used signals.

Basic rules

• Always point to safety, away from danger
• Repeat the signal to indicate you understood it

Basic paddle/hand signals

Stop

Lift your paddle above your head, or spread your arms. Move hands slightly up and down to attract focus to your signal.

Move to an eddy as soon as possible, wait for further signaling.

One Down

Point out 1 with your paddle or finger.

At this signal, one paddler comes down. Repeat the signal before leaving.

Help/Emergency

Wave your hand or paddle. Give 3 blows on your whistle.

I'm OK, are you OK?

Tap your head with your hand.

Showing you're ok, asking if the other person is ok

The above signals are the American Whitewater approved river signals. I added a couple more I think are usefull.

I'm not ok, I want to get of the river

movement is like slicing of your head with your hand

You're not ok. You want to get of the river, or you can't do the required action on the river.

Not runnable

Make a cross with your arms above your head. The upcoming section is not runnable.

Paddle directions

Point to the side of the river where the paddler should go, not where he/she shouldn't be.

Eddy out

Make a circle with your hand, followed by pointing to the river side where to eddy out

Scouting

Point with your index and middle finger to your eyes and move your hand further away (I'm watching you move). We go out and scout the section.

Walking

Make a walking move with your fingers on your other arm. Get out and carry the section.

Whistle signals

These are not really standardized, but I like the following sequence

1 blow: attention, something or someone requires attention
2 blows: a swimmer, help where possible
3 blows: emergency. Get yourself to safety. Rescue people, move quickly to help  

When using audible signals to indicate if someone can paddle down, always make sure if you miss one signal, nobody moves:

1 blow: don't move
2 blows: come down

If with the roaring of the river 1 blow is missed, then no paddler comes down by accident. If you switch the signals, a paddler might go down a section where he or she doesn't want to be!