It was designed in the Soviet Union in 1974. It was called the Alexeyev/Sukhoi Albatros and was intended to achieve a launch of a spacecraft from a ship. It was not implemented for a specific reason which we will mention below.
The spacecraft would be mounted on the rocket body that would carry it into space. The missile in turn would be on the surface of a flat ship. These 3 would develop speed on the surface of the sea and when they reached 180 km/h the rocket and boat could take off.
That way there would be no need for a launch pad or take-off duct.
The ship would weigh 2,000 tons and be 91 meters long. Its name would be Albatros Momentum Block. The missile would be 70 meters long and weigh 1,250 tons. Its name would be Albatros Carrier Aircraft. The spacecraft would be 49 meters long and weigh 320 tons. Its name would be Albatros Rocketplan.
The reason it was not built is because in the water when the speed exceeds 110 km/h, it is dangerous because of the shock waves that are created.
[Source: http://www.newatlas.com]
