Two ‘milestone’ submarines have been unveiled, vessels that according to the maker can be transformed into underwater casinos, wedding and private dining venues and configured for cocktail parties.

Florida-based Marine engineering firm Triton Submarines said it ‘threw out the rule book’ when it came to designing its new first-of-their-kind Triton 660/9 and 660/7 AVA submarines.

The result is a twin set of submarines capable of reaching depths as great as 200m (660ft) that each come with a 3.6-metre- (12ft) wide interior space that ‘feels like a regular room rather than a submersible’ and can be reconfigured for all sorts of entertainment experiences….