It comes as no surprise that the U.S. Navy boasts some of the most advanced drones in the world. Just look at the Sea Avenger or the stealth-like X-47B and you can understand why. It’s in that regard that the Navy is developing a new type of UAV that can not only fly but swim as well.
They call it “Flimmer” (Flying/Swimmer) and it features a pair of unusual wings that have fins on both ends that unfold when the craft submerges underwater, allowing it to swim. To give it more stability in the water, the NRL (Naval Research Laboratory) team outfitted it with another pair of foldout fins as well as dual bladders that fill with water to maintain a neutral buoyancy.
The UAV/UUV has a cruising speed of about 57mph, however it has a much slower swim speed of only 11mph when submerged. While that may not sound like much, consider what the Navy wants it for: tracking submarines.
At this point in time, the Navy relies on SONAR-equipped stationary buoys to track submarines, but when those subs move out of range, tracking is lost. The Flimmer on the other hand is capable of continuous tracking even as most subs cruise along at 30mph when submerged.
If an enemy sub is detected, the Navy simply launches the Flimmer, after which it enters the water and tracks it until the sub increases speed. It can then return to the air and submerge once again to echo-locate the sub. Simply put, there is no escape.
The NRL team has been developing the Flimmer for two years and the “flying submarine” will undoubtedly undergo a few revisions before it enters service.
For further information take a look at the NRL’s Spectra publication.