Water is the "most illogical" behaving substance on earth - and it was exactly these characteristics which made life possible on our planet:

    

1. Water consists of the elements hydrogen and oxygen. Both are gases. Together they are, however, liquid at normal temperature and pressure.
2. The human body consists of 66% to 75% water.
3. The earth is covered with 70% water - of which:
• 97.0% is sea water.
• 2.6% is fresh water.
• 0.3% is potable water.
4. Water is the only substance on earth occurring in all THREE state conditions:
• Gas (at temperatures greater than 100°C water exists in clouds).
• Liquid (for temperatures between 0°C and 100°C at atmospheric pressure).
• Solid (for temperatures below 0°C).
5. Water has its largest density at +4°C, but still remains liquid.
6. Water has its lowest density at a temperature of 37°C.
7. Water in the solid state (ice) is lighter than in the liquid condition and thus the colder ice floats on the warmer water.
8. Physically seen the freezing point of water should be at -120°C and the boiling point at -75°C. However, the freezing point is actually at 0°C and the boiling point at +100°C.
9. The difference between freezing point and boiling point should be in range of 23 to 30°C. It is, however, 100°C.
10. If very high pressure is supplied to water the temperature does not rise above 37°C.
11. The minimum thermal capacity of water is found at +37°C and this can thus regulate the temperature of the human body.
12. Additionally, water is an outstanding solvent - of the 103 natural elements on earth 84 are soluble in water.

Links:
Water properties
http://www.lsbu.ac.uk/water/data.html