Submarine sends underwater e-mail

Undersea communication is now easier

Using underwater sound waves, e-mail has been sent longer distances under the ocean than ever before.

It was also the first time a submerged and moving submarine was able to communicate without giving away its position by surfacing or raising an antenna.

In tests last month, the US Navy used equipment developed by technology company Benthos to send e-mails from a submarine off the coast of California to a naval base in San Diego and to other underwater modems.

While cruising at a depth of 130 meters (400 feet), the USS Dolphin was able to transmit data up to a distance of five kilometres (three miles) to a relayer buoy. This then transferred the messages to land, according to Benthos chief executive John Coughlin.

He said that underwater e-mails had been sent before but the new method improved the distance, speed and reliability of the transmission.

Slowly but surely

The modem sends digital data underwater, including words and pictures, using sound energy transmitted from acoustic modems. Normal electromagnetic waves cannot penetrate water efficiently.

Although slow in comparison to conventional modems, with a speed of just 2,400 bytes per second, Mr Coughlin emphasised the success of the new underwater system: "When you're using sound waves to do it, that's pretty fast."

This technology could, in the future, be utilised by companies involved in scientific and commercial underwater exploration.

But it is in the defence sector that the impact could be most felt.

For instance, enemy submarines could be tracked more accurately and efficiently if surface vessels and their underwater allies can communicate by e-mail.

The technology was developed using a grant from the US Navy, showing that the potential benefits of this technology are been taken seriously in the US.