New building materials for cruise ships hulls
Using new alloys when building ships have been proposed, which should result in a 30% reduction of weight of the ships. Not only are they light, but they are also as strong as the contemporary high grade steel and iron used to build ships. As explained earlier, this results in less fuel consumption due to drag reduction
Changing the structure of the ship
More hydrodynamic shapes help in reducing the fuel consumption and making the throughput of the engine power more efficient. New techniques of using hulls which are more rounded at top allow the ship to glide over its surface rather than cutting the water and pushing it aside, which is exactly what the traditional V-shaped hulls do. Usage of such hulls help in increasing engine life and reducing fuel consumption.
Improved aerodynamics can be used on smaller boats, but they do not make much difference on the huge cruise ships.
More efficient engines for cruise liners
Engines that use the revolutionary wave technology which is still in experimental stage should be adapted to and building ships with such revolutionary technologies should be encouraged, even though they might not be as efficient as expected. (Constant development should help, of course.)
Low sulphur fuels for ship engines
Low sulphur diesel is said to cut emissions substantially. Moreover using engines that efficiently use the fuel are recommended because not much fuel is wasted in this process.
Lighter weight interior material fittings inside cruise ship
More usage of light weight materials inside the ship will contribute to reducing the ship from becoming more heavier than it is already is.
Hence we can say that despite providing the best of luxuries, the cruise liners are playing a role in terms of leaving their carbon footprints. Shipyards, naval architects, and marine engineers should all be able to contribute in their own ways to make these ships more environmentally friendly.