http://www.gmi.edu/~drussell/Demos/refract/refract.html
The difference in medium would cause differences in wavelength when the sound goes from water to air, but the frequency (which is what we hear) is constant. Hence the speed of sound in the water is irrelevant.
Out of curiosity, I looked into the impact on wavelength.
v = speed of sound
B = bulk modulus, constant for water
rho = density
v = sqrt(B/rho)
with a 5% change over 100 degrees, the speed of sound changes by about 2.6%. v = f*lambda, f = constant, so the wavelength changes also by about 2.6%. Not that this means anything for our perception of sound, as noted above. Even if frequency somehow changed by this amount, the difference between, say, 500 and 510 Hz isn't the kind of thing that's going to make us say "whoa, it sounds totally different."
Changing the subject, I also like LStanley's answer.