As World War II was drawing to its final conclusion, German naval designers in late 1944 were proposing some truly radical designs under desperate circumstances. Among them was the final evolutionary step of the K-Verband development for their hydrofoil attack boat projects.
Designated the TR-5b, the futuristic Tragflügelboot concept called for the addition of twin turbojets to be added to a VS- type hydrofoil to create a high-speed, heavily-armed hydrofoil fast attack craft. The turbojets (two Jumo 004s or He S 011s) were to be mated to the hydrofoil to allow a drastic increase of speed during the final attack phase and disengagement of enemy vessels.
Although tests with the radio-controlled jet powered boat Tornado of 1944 revealed several problems with this kind of propulsion (only viable in calm seas and with persistent control problems), the addition of turbojets for the TR-5b was seen as a possible solution to increase the chance of surviving an attack against Allied ships.
Armament has never been disclosed for this vessel but from the depictions looks like standard S-boot armament of guns, torpedoes, or mines.
However, this project arrived too late and held no significant advantage over the German S-boots. Likewise, the German explosive speedboats also came to nothing except some experimentation. The TR-5b was to start construction in early 1945 but was cancelled instead by the realities of the naval war.