The Navy has developed a way of transmitting emails underwater, New Scientist reports.

Until now, the e-revolution has been of limited benefit to Navy submariners, since radio waves do not travel well through water. To transmit data, submarines have had to come to the surface, thus revealing their position to the enemy.

The new technology uses an acoustic modem that pushes out pressure waves, enabling data to be transferred while still submerged.

US Navy submarine USS Dolphin transmitted an email consisting of pictures and text over a distance of five kilometres at a rate of 2.4Kbps to a radio buoy.

Let's just hope no one sends any really bigattachments. ®

A reader has informed us that this is not a new phenomenon, merely something of a “water speed” record. It seems that the longer wavelengths have been used for decades, since they carry over huge distances, but only went at a fairly meagre 600bps.