ΔE 15.7, loose: different enough that you should pick on purpose. Turquoise is a little darker, more saturated, cooler than Surf Aqua.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Turquoise is a little darker, more saturated, cooler than Surf Aqua.
The same difference applies the other way round: Surf Aqua is a little lighter, 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 Surf Aqua on the colour wheel See Turquoise on the colour wheel
All matches: Surf Aqua equivalents · Turquoise equivalents