There is no universal whistle signal system for canyoning. Each country has its own system. Some countries have more than one system that are significantly different from each other. Some are relatively complex similar to Morse code. I asked some international canyoning friends for their whistle systems. Here are some responses: Belgium 1) Stop - 1 whistle blast. 2) Free - 2 whistle blasts. 3) Down - 3 whistle blasts. 4) Up - 4 whistle blasts. Germany One stop Two ok Three give me rope Four pull the rope up Many whistles: danger Italy a) Stop (stop) - 1 whistle blast b) Down (ca-la) - 2 whistle blasts c) Free (li-be-ra) - 3 whistle blasts d) Up (re-cu-pe-ra) - 4 whistle blasts Britain a) Stop (stop) - 1 whistle b) Free (off rope) - 2 whistle blasts c) Down (lo-wer rope) - 3 whistle blasts d) Up (up rope) - 2 (long) whistle blasts Current whistle signals are often based on similarity with the syllables in the words of that language: “stop, down, up and free.” Each language may be quite different in the number of syllables for the equivalent of those commands. Assume one of the whistle blasts from the person on rope was not heard by the operator at the anchor. For example, a “down” command that is not entirely received. In the above examples, an Italian operator will “stop” because he only heard one of the two whistles. While a British operator who heard only two of the three whistle blasts will think that his mate completed his rappel and is off rope. The operator might leave the rope without control. This could be dangerous. A better whistle coding system would assign rules that are meant to minimize the impact in case the rope operator at the anchor cannot hear all of the whistle blasts. This is much different logic than having one whistle blast for each syllable of the word being coded for. The following was suggested by some very experienced European canyoneers who have been instrumental in the development of the sport. Proposed international whistle system: a) Stop - 1 whistle blast. In dangerous situations where progress needs to halt, one whistle blast is simple and fast. Perhaps the person actually whistled more than once. The likelihood of harm to him/her is low by stopping. The person on rope can whistle again in order to clarify. b) Down - 2 whistle blasts. Two whistle blasts are relatively easy to perform in a dangerous situation. c) Free- 3 whistle blasts. The person does not have difficulties. Hence giving three whistle blasts is very easy to do. If the operator at the anchor only hears two or one, this does not significantly change anything. The person on rope either is lowered or remains stationary. d) Up- 4 whistle blasts. Used to retrieve the rope that is too long. If all four whistle blasts are not heard, there is no harm. The message can be repeated until understood. e) Multiple whistle blasts. Used for an emergency. Should be obvious to the operator that there are not just one, two, three or four blasts. Admittedly this is different than the whistle signals I routinely use. It is different than the signals used by the rescue team I am a member of. Ultimately each group, at the beginning of the day, must agree on the signals to be used. However, it would be nice if the international canyon community could agree on a standard. It would make international canyon festivals a little safer.