ΔE 26.9, loose: different enough that you should pick on purpose. Light Sea Blue is a little darker, cooler than Cobalt Teal.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 27). Light Sea Blue is a little darker, cooler than Cobalt Teal.
The same difference applies the other way round: Cobalt Teal is a little lighter, 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 Cobalt Teal on the colour wheel See Light Sea Blue on the colour wheel
All matches: Cobalt Teal equivalents · Light Sea Blue equivalents