Environmental charity Earthwatch is organising two 13-day expeditions diving the WW2 wrecks of Truk Lagoon in Chu'uk, Micronesia, and is looking for volunteers to assist in the survey of this famous site.
It says you can help marine scientists and archaeologists to 'document and help protect the lagoon's rich historic and biological heritage' by gathering and recording information on the decay rates of the many wrecks. Departure dates are 20 October to 1 November and 3-15 November 2008. The cost of ?1795 covers training, food and accommodation, but you have to pay for all travel on top of that. Divers should have at least two years' experience.