SUBMARINES ARE ABOUT TO NAVIGATE BY GRAVITY.
A nuclear submarine's one job is to stay hidden. Though it's one problem is it can't know exactly where it is without surfacing. GPS doesn't penetrate water and radio doesn't either. So subs navigate by dead reckoning, inertial sensors that drift a little more every hour, and periodically they have to come up, expose an antenna, and risk detection to get a fix.
For seventy years that tradeoff, hide or know where you are, has been the central vulnerability of the most expensive weapons on earth.
Quantum sensors end this as a quantum gravimeter reads Earth's gravitational field, which has a unique fingerprint at every location and passes through water like it isn't there. Match the reading to a gravity map and the sub knows its position, at depth, forever, emitting nothing, receiving nothing, never surfacing. Nothing to jam, nothing to spoof, nothing to detect.
Last month a ship navigated the Coral Sea with GPS off on a quantum gravimeter, one nautical mile accuracy, the sensor sitting in a passenger cabin with no stabilization rig. The UK Royal Navy is running Infleqtion's quantum clock and navigation trials. The Pentagon's Farseer program is funding maritime quantum gravimeters specifically.
$INFQ $IONQ $QBTS