Chinook III/IV

Although based on the same hull shape as Chinook I and Chinook II, Chinook III is a clean sheet design that involved the layup of the UVSRC's second submarine hull. Chinook III used a revised layup process designed to optimize submarine assembly and maintenance. The main external difference is the submarine hull being composed of 2 hull panels instead of the previous 4. Internally, Chinook IV uses revised mounting points to increase the modularity of the submarine subsystems

Chinook III was never raced due to the COVID-19 pandemic. The design report for Chinook III was presented to judges for the 16th biennial virtual ISR, where the design of the drivetrain earned the UVSRC an Honorable mention.

In 2022, the UVSRC was able to resume normal activity after the COVID-19 pandemic, The incomplete Chinook III was pulled out of storage, and was renumbered Chinook IV since Chinook III competed in the virtual ISR 16. The UVSRC completed the implementation of the modular mounting system (the weight rail) for Chinook IV, and added a set of stability fins behind the main control surfaces on the hull, as it was found at ISR 15 that the removal of the kort nozzle that was featured on Chinook I pushed the center of pressure on the submarine in front of the submarine's center of mass, causing it to become unstable at high speeds.

Chinook IV competed at eISR 2022 at the Qinetic Basin in Gosport, England. The submarine achieved the highest speed at competition, and came in 3rd overall, Surpassing Chinook I's performance at eISR 2018.