Actuators based on soft elastomers offer significant advantages to the field of robotics, providing greater adaptability, improving collision resilience, and enabling shape-morphing. Thus, soft fluidic actuators have seen an expansion in their fields of application. Closed-cycle hydraulic systems are pressure agnostic, enabling their deployment in extremely high-pressure conditions, such as deep-sea environments. However, soft actuators have not been widely adopted on unmanned underwater vehicle control surfaces for deep-sea exploration due to their unpredictable hydrodynamic behavior when camber-morphing is applied. This study presents the design and characterization of a soft wing and investigates its feasibility for integration into an underwater glider. It is found that the morphing wing enables the glider to adjust the lift-to-drag ratio to adapt to different flow conditions. At the operational angle of attack of 12.5°, the lift-to-drag ratio ranges from −70% to +10% compared to a rigid version. Furthermore, it reduces the need for internal moving parts and increases maneuverability. The findings lay the groundwork for the real-world deployment of soft robotic principles capable of outperforming existing rigid systems. With the herein-described methods, soft morphing capabilities can be enabled on other vehicles.