The deep diving submersible Alvin was built in 1964, and after numerous refits currently has a depth rating of 4500m. WHOI has announced that a new submersible will be built to replace Alvin with an operational depth of 6500m. This will allow scientific research missions to cover some ninety percent of the seafloor. The four year design and construction programme will cost US$21.6 million. Trials are expected to take place in 2008.
Source: Silvercrest Submarines (UK)