The speed of cruise ships can vary depending on factors such as the size and design of the ship, the itinerary, weather conditions, and fuel efficiency considerations. However, most cruise ships typically travel at speeds ranging from 20 to 24 knots (about 23 to 28 miles per hour or 37 to 45 kilometers per hour) while at sea. Some newer and larger cruise ships may be capable of reaching slightly higher speeds.
It's worth noting that cruise ships often operate at speeds that balance fuel efficiency with passenger comfort and safety. Additionally, speed may vary during different parts of the journey, such as while navigating through ports, channels, or areas with speed restrictions.