Assisted takeoff is one of several technologies that can possibly boost efficiency of aircraft, as said:
Listen to the changing sound of engines during flight and it’s obvious: an aircraft draws on its power reserves more during takeoff than at any other time. The power needed to take off is determined based on a number of factors - including runway length, wind speed, temperature, and the weight of the aircraft itself.
However, this takeoff power only is required for a very brief portion of the total flight. Once cruising in the sky overhead, an aircraft doesn’t need as much to maintain altitude. So why not source the energy required at takeoff from an innovation installed on the ground? Can the burden (and weight) be removed from the aircraft itself?
An assisted takeoff – using some form of propelled acceleration – would mean aircraft could be lighter, with smaller engines consuming less fuel. …
Nevertheless, in a later part of the article, they suggested using normal landing gear or similar cart also for landing. However, I started to wonder, because such cart can be somewhat hard to land on. Technically speaking some cases a different place was being considered as much more forgiving:
(Original image source may be http://www.spacefacts.de/graph/drawing/drawings2/apollo-15_landing.jpg)
So I want to combine those two ideas. Would an aircraft that uses assisted takeoff and water landing be realistic? (I am especially asking whether water landing would provide some weight savings, instead of carrying whole landing gear. By realistic, I ask whether it would provide any saving in weight in comparison to landing on ground.) I assume that aircraft would have engines high enough so their contact with water would not be an issue. I also assume that hauling this aircraft or getting compatible infrastructure is not a problem.