What transmitter power should Canadian amateur radio operators use at all times?

Innovation, Science and Economic Development Canada (ISED) rules state that amateur radio operators must always use the minimum transmitter power necessary to carry out the desired communication. This fundamental rule is designed to reduce congestion on the amateur bands and minimize unnecessary interference to other stations. While your specific certification class grants you a maximum legal power limit (such as 560 watts or 2250 watts), it is bad practice and against regulations to routinely transmit at maximum power when a lower power setting would comfortably maintain the contact.