What indicates an emergency on board of a boat?

An emergency on board a boat is typically indicated by signals such as loud alarms, flashing lights, or verbal announcements from the crew. Other signs include sudden changes in the boat's stability, loss of power, or visible distress among passengers or crew. Additionally, specific distress signals, such as flares or the activation of an EPIRB (Emergency Position Indicating Radio Beacon), can also indicate an emergency situation. Immediate action and communication are crucial in such instances to ensure safety.