ΔE 21.4, loose: different enough that you should pick on purpose. Surf Aqua is noticeably lighter, more saturated, cooler than Stegadon Scale Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Surf Aqua is noticeably lighter, more saturated, cooler than Stegadon Scale Green.
The same difference applies the other way round: Stegadon Scale Green is noticeably darker, more muted, warmer.
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 Stegadon Scale Green on the colour wheel See Surf Aqua on the colour wheel
All matches: Stegadon Scale Green equivalents · Surf Aqua equivalents