Maybe Electric Ships One Day WIth Fuel Cells and Hydrogen

Ocean shipping burns dirty fossil fuel contributing mightily to global warming gasses. If shpping were to transition to electric engines with large hydrogen fuel cells or hydrates and even carbohydrates for hydrogen storage the ocean could become a somewhat cleaner environment. Ships would still be a nuisance and threat to whales though.

https://insideclimatenews.org/news/13042018/ocean-shipping-imo-agreement-reduce-climate-change-emissions-fuel-oil-zero-carbon-clean-energy-technology

wikipedia entry on hydrogen storage in carbohydrates; "Carbohydrates (polymeric C₆H₁₀O₅) releases H₂ in a bioreformer mediated by the enzyme cocktail—cell-free synthetic pathway biotransformation. Carbohydrate provides high hydrogen storage densities as a liquid with mild pressurization and cryogenic constraints: It can also be stored as a solid powder. Carbohydrate is the most abundant renewable bioresource in the world.

In May 2007 biochemical engineers from the Virginia Polytechnic Institute and State University and biologists and chemists from the Oak Ridge National Laboratory announced a method of producing high-yield pure hydrogen from starch and water.^[20] In 2009, they demonstrated to produce nearly 12 moles of hydrogen per glucose unit from cellulosic materials and water.^[21] Thanks to complete conversion and modest reaction conditions, they propose to use carbohydrate as a high energy density hydrogen carrier with a density of 14.8 wt%.^{[22]" -} https://en.wikipedia.org/wiki/Hydrogen_storage