Why doesn't Wi-Fi work underwater? - 1

I know it's obviously not MEANT to work underwater, but why does it not work AT ALL? I went underwater with my iPhone 5 in a waterproof case and as soon as I went in the water I got zero reception.

Poor Wi-Fi connection? Wi-Fi does work underwater.

Outside the visible spectrum, electromagnetic waves travel slower in water, but that doesn't affect the data rate. It will just add maybe a microsecond to packet response times. The real problem is absorption. Water is a strong absorber of electromagnetic waves outside a narrow band in the visible spectrum. For frequencies in the 1-10 GHz range, where most fast Wi-Fi lives, the absorption constant is greater than 10 cm^-1, which means that a signal loses half it's strength in (1 / (10 cm^-1. = 0.1 cm or less. The absorption gets smaller at lower frequencies, but doesn't do so quickly. Military grade VLF transmitters can penetrate around 200m of sea water, this is at frequencies of 3-30 KHz. The data rate in bits would be far less than dial-up modems at that frequency.