Churchill Capital Corp X and Infleqtion, in collaboration with the Royal Navy, announced the successful demonstration of the world's first quantum optical atomic clock deployed on an underwater autonomous submarine. The trial, which has already taken place, integrated Infleqtion's Tiqker optical atomic clock into the Royal Navy's Excalibur testbed submarine. The results showed that the clock operated reliably during multiple dives, proving its potential for resilient positioning, navigation, and timing $(PNT)$ in GPS-denied environments. Further performance benchmarking is planned, but this trial marks a significant step forward in applying advanced quantum timing technology to real-world naval operations.