[pjc50]

Exactly. In fact, for some applications GE are using modified aircraft turbines on ships: https://fas.org/man/dod-101/sys/ship/eng/lm2500.htm

Those are for military use, where speed matters but money is basically unlimited.

[rkangel]

Money is unlimited, but fuel efficiency isn't just about money for the military. More fuel usage means more supply lines. That's less of an issue for navies than armies but still important.