When it comes to naval vessels, and in particular submarines, enormous importance–and secrecy–is placed on their prop designs. It is not an exaggeration to say that in some parts of the world, a photo like this, if based in reality, could lead to the severest of penalties.
But we are feeling mellow today, and have decided to share a few tidbits. In the spirit of modern statecraft, we will just say that it is up to the viewer to determine what is real and what is intended as disinformation. The blades above might be a Photoshop creation. Then again they could be based in reality.
Back in December we gave you a look at what was then described as a propeller for FPB 78-1. Prudence dictates that we not give away key engineering developments, so why publish such important data when would-be competitors might be lurking? The FPB on which these props may or may not be fitted perhaps does not exist, or could be real.