Davy Jones's locker might soon be a popular e-mail address. The U.S. Navy has demonstrated that wireless access to the Internet can extend to underwater domains. At the end of May, the submarine USS Dolphin sent the first subsea e-mail while "surfing" 400 feet deep.
Sending digital data through the ocean is tricky because, ironically, water is such a good transmission medium. Since sound waves can travel hundreds of miles, the ocean is flooded with noise. Sifting out the sound of a given digital bit is complicated by the fact that the same digital-bit sound can arrive many times: Echoes also travel long distances under water, bouncing off sub-sea cliffs and canyons and boundaries between water layers of different temperatures.
Using special acoustic modems from Benthos Inc. in North Falmouth, Mass., the Dolphin sent Internet mail through several miles of noisy water. Buoys outfitted with savvy Benthos software filtered out the traffic, then relayed it via satellite to shore. The data crawled at just 2,400 bits per second, but Benthos President John L. Coughlin says his next-generation modems will run four times as fast.