Air Rope Plane

[edited the idea's name] Wait, for the sea the idea gets even better!

First for ground based propulsion:

I used to have a model plane where I would pull a rope while turning, and the plane at the end would fly up, see link. Taking this idea a bit further: You have a plane flying - elevated by standard engine power thrusting it forward, and its wings doing the elevation work. Then up comes a tiny automatic pilot-less plane trailing a rope behind it, and connecting to the plain. The rope is extremely lightweight but very strong. (These exist). Once the plane is connected the rope pulls the plane forward (and the wings keep it elevated) much like a kite with a kid running on the ground. There should be very little friction, but the loss of power from a jet engine pushing air instead of pulling a solid rope is saved.

At the height of movement the tiny plane with its rope is released and the large plane continues in its sling path.

2. Now for the sea: Here the idea is much simpler and more elegant. Combine the aerodynamics and almost frictionless movement of a speedy airplane, with solid propulsion by pulling a rope against the high friction of a parachute or sail submerged in water. The plane itself swings a rope with a small parachute forward. then pulls on it, causing the parachute to open under water. It then pulls on the rope for a distance, until reaching the optimum height and distance (the thrust on the wings give the plane its elevation) when, using a a simple mechanical device, the parachute releases one side of its tension and the water is freed, the rope is pulled in to some distance, and swung forward again. Two ropes like this could create a "walking on water" effect.