On flatwater only because of the distance and the covering of objects, on whitewater and on the sea because of the noise of the water the communication options are limited. The table contains the most important and most frequently used signals.
The International Rafting Federation (IRF) shows you the complete and current standard signal system here:irf_river_signals_2010
Under the current system, the IRF uses a different sign for “Everything is OK.” and “Last Ship. / Out.”. The table does not include all IRF signals and contains signals from different systems as well.