What is the result you want to achieve? Are you building a scale model of a submarine, for example, and so, you're striving for as much realism as possible? Using pictures of explosions probably won't work right, in that case.
There is a ship modeler by the name of Won-Hui Lee, who produces amazing models of ships, including dioramas depicting underwater scenes. He made a diorama earlier this year, or last year, of a subchaser depth-charging a submarine, and he depicted the underwater blasts very convincingly. There were photos in
FineScale Modeler magazine, if I remember correctly. He's a member of the Model Warships forum; here's his gallery there:
http://www.modelshipgallery.com/gallery/index-gallery.html
But I've heard from a buddy of mine, who is also a member of the forum there, that Mr. Lee hasn't answered any requests for explanations of his technique. It looks like he casts resin but leaves a void for the burst. He also lights the burst, so we see the flash and the ball of air released in the explosion.
If I can find photos of the diorama I remember, I'll post them back here so you can see. In the meantime, I recommend browsing Lee's gallery, even for those who aren't necessarily interested in building any ship models. He does outstanding work.
Prost!
Brad
