We have seen a significant long-term R&D investment but all the nice rotary engines are in prop planes.

Edit: since you mention a ship, some use large opposed-pistol Diesel engines (two oppositely meeting pistons around the combustion chamber per cylinder which also allows the cylinder to be much wider)... don’t see these in either planes or cars... Hydrogen power?—- Hydrogen is difficult to keep contained because it escapes through anything over time unless we put heavy ceramic tanks in our cars.