Seaweb nodes are capable of exchanging information through dozens of kilometres of water. Such long ranges, however, require the use of low-frequency sound waves, which reduces the data rate. Joseph Rice, the project’s leader, says a Seaweb node can send a low-resolution photo to another one 5km away in five seconds—two seconds to emit the sound waves, and another three for them to travel that far. In seawater acoustic waves carry only a few thousand bits of data per second, but they travel at 5,600kph (3,500mph)—five times the speed of sound in air.
It is hardly broadband, but it can be used to connect submarines and warships to sensors and roving subsea drones, also known as unmanned underwater vehicles (UUVs). Mr Rice imagines that UUVs might deploy sensor nodes and could visit them when required to download the data they have collected in large quantities. Sensors could also alert UUVs of any unusual readings that require investigation.