A rudder is included with the Seaker models. An optional rudder is available for the Helios models. The rudder is useful when paddling the Helios as a double when heavily loaded while touring on open water. The rudder keeps the boat tracking straight so that all paddle strokes can go toward thrust, not steering. The rudder also helps in crosswinds when more lightly loaded. When paddling the boat as a single, or when descending swift rivers, the rudder is not needed. Some experienced paddlers eschew the rudder in all conditions, but we generally recommend it for touring doubles. The Safari, Solar, and Sunny come with removable tracking fins.