– Defense News – Unmanned systems are commonplace in the world of aviation. But it wasn’t long ago that they were more of an oddity for world militaries. That changed when technological developments finally let systems operate for long stretches of time, giving operators a near-permanent eye in the sky. Once that barrier was breached, UAVs could be used for all kinds of applications. Is a similar breakthrough coming for unmanned systems that operate underwater? Boeing believes so — and that it will happen within the next two years.