International submarine race takes place in UK
29 June 2012 Last updated at 00:13 BST
Europe's largest freshwater tank, QinetiQ's Ocean Basin in Gosport, is the venue for this year's International Submarine Races event.
It is the first time the competition - which pits human-powered submarines against each other - has taken place outside the US.
The UK is represented by Bath University, which will be competing against two teams from Canada and three from the US.
Here engineers from the UK team explain how they have designed their submarine.
Video produced by Dougal Shaw and Dan Curtis