ΔE 8.4, close: similar, with a visible difference side by side. Imperial Navy is more saturated, warmer than Marine Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Imperial Navy is more saturated, warmer than Marine Blue.
The same difference applies the other way round: Marine Blue is more muted, cooler.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Marine Blue on the colour wheel See Imperial Navy on the colour wheel
All matches: Marine Blue equivalents · Imperial Navy equivalents