Continuum manipulators are high degree of freedom structures that can use their increased degrees of freedom to navigate through an environment with obstacles. This type of manipulator is underactuated, which make them promising for adapting to their environments. However, current research is mainly focused on accurate positioning and obstacle avoidance, while the advantages of underactuated systems remain unused. Therefore this paper proposes a new design and approach of a continuum manipulator, which can navigate through an environment with obstacles by passively shaping the manipulator along the obstacles. The proposed design consists of a sequence of crosslink segments, where steering is done by an antagonistic pair of tendons and forward movement is done by a single pushing force at the base of the manipulator. Analytical models and a prototype show that this manipulator has a highly increased range of motion per segment compared with similar systems. The results also show that the manipulator is able to reach a target in a multi-obstacle environment using a simple binary control system with low input forces.