The Siebel ferry (Siebelfähre) was a shallow-draft catamaran landing craft operated by Germany's Wehrmacht during World War II.

It served a variety of roles (transport, flak ship, gunboat, convoy escort, minelayer) in the Mediterranean, Baltic and Black Seas as well as along the English Channel.

As German Army preparations for Operation Sea Lion got under way in July 1940, frustration soon grew over when and what types of ships the Kriegsmarine would supply for use in the planned Channel crossing.

The immense task of converting hundreds of inland river barges and motor coasters into proper landing craft began, and the Kriegsmarine was unable to give the Army a date for their availability.

[2] Anxious to begin landing exercises, Generalfeldmarschall Walther von Brauchitsch finally ordered General of Engineers Jacob to build sea-going transports for the army.

The battalion moved to Carteret on the western side of the Cotentin Peninsula, and the men of this unit searched the French countryside for materials with which to construct self-propelled rafts and ferries.

The answer interested Siebel and led him to ponder how to ferry troops and heavy equipment across the English Channel given the time and materials.

[3] Pionier-Battalion 47 began experimenting with a host of makeshift materials for constructing powered rafts, including wine barrels, tree trunks, kapok fibre-filled sacks and ship's canvas.

[6] Colonel Siebel, assigned a Sonderkommando (special command) for improvising the Luftwaffe invasion craft, built a prototype with two heavy bridging pontoons spaced 6 m (19 ft 8 in) apart in a catamaran arrangement connected by steel cross-beams.

But because of the vessel's broad beam, the crews had to react simultaneously to requests for changes in speed or the ferry would begin turning, a movement the rudders could barely counteract.

This greatly improved manoeuvrability, but the aircraft engines were noisy, prevented voice communication on deck, and consumed large amounts of fuel.

The Luftwaffe mounted various-sized flak pieces on the ferries, and tested their suitability for engaging both air and surface targets while at sea.

[12] With its simplicity of design, sturdy construction, good sea-keeping, and the ease with which it could be dismantled and shipped via rail to virtually any point on the Continent, the Siebel ferry proved a useful and adaptable amphibious vessel for transporting troops, vehicles, and supplies across open water wherever needed by Germans.