microwave penitration in water

hi
can any one tell me if microwaves are reflected back by water?
how to calculate the exact frequency which can penetrate water surface?
thanks

- an incoming wave will be mostly reflected at all microwave frequencies due to the high permittivity (Er) of water
- in addition, absorption of the transmitted part will be high
- there is no "exact frequency" rather than an increasing absorption of higher frequencies
- quantitative data of complex permittivity (including the absorption) versus frequency can be found in profound RF literature. You should be able to find some on the internet.

If you have a more specific question, it can be possibly answered by forum members.