Solar Submarine for Greta

Greta Thunberg is in the news as Time's person of the year, a well- and hard- earned title considering she has endured two trips across the Atlantic by sailboat this year.

To honor Greta's endurance and devotion to resolving climate unsustainability, effort should be put toward designing better and more comfortable zero-emissions transcontinental ocean-faring vessels. It's not just for Greta but for all future generations to have permanent sustainability.

With a little research, I've found a few renewable-power designs that could be combined to create a more effective and comfortable solar submarine system.

The first is Project Goldfish https://newatlas.com/the-solar-powered-submarine/10426/, by Swiss energy company BKW, which uses a solar platform to power a submarine below the surface. Such a design, if implemented for a transcontinental vessel, would allow passengers to cruise below the ocean surface tethered by cable to a solar surface platform so that they would be insulated from turbulence on the surface, which led Greta to describe her first three-week trip as being like, "camping on a roller-coaster."

Solar catamarans such as Silent 55 https://newatlas.com/silent-55-solar-powered-ocean-going-catamaran/60207/ suspend a solar panel array between two hulls. Some vessels use Lithium batteries to store energy, but why not use solar power to electrolyze sea water into hydrogen and oxygen, which could be stored in tanks and then combusted to generate electricity for the motors and submarine below and/or combusted directly to power motors?

Adding a skysail https://en.wikipedia.org/wiki/Skysail to the system could also incorporate wind power as propulsion-assist, which would add power/speed to the combined catamaran-submarine system.

Between solar-electric motors, sea water hydrolysis, hydrogen/oxygen combustion power, and skysails or some other more conventional sail-system, transcontinental submarine travel could become a more comfortable and effective mode of transcontinental zero-emissions travel.