Chinook III and 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. The UVSRC elected to layup a new hull for Chinook III to satisfy the following goals:
Demonstrate hull layup techniques to new UVSRC members, as most of the original club members were nearing graduation.
Increase pilot safety by decreasing snagging points in the hull where the hull pieces latched together.
Redesign the submarine to split into 2 halves instead of 4 quarters, as it was found that latching the 4 quarters together underwater was difficult due to their buoyancy.
Implement a new modular mounting system to increase the flexibility in designing 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.