It's one of the most revolutionary developments in marine navigation: the universal automatic identification system (AIS). The transponder broadcasts a broad range of information about a ship on VHF marine radio, including its position, speed, direction, cargo, classification and destination. An AIS unit transmits all this information in real time, ship to ship and ship to shore, without a central…

The search for oil and gas has been a driving force in the development of dynamic positioning systems. Drill rigs, for obvious reasons, must maintain a fixed position above the ocean floor. As rigs moved off the continental shelf into water too deep for jack-up rigs or where conventional mooring or anchoring systems were not feasible, computer controlled DP systems…