Unknown Dolphin badge?

[sailorbear]

Hi all, anyone able to positively identify this badge? It looks like a stylised dolphin? and not dissimilar to the ones used by the submarine service's of Peru, Venezuela, Norway, Japan, India, Canada, the US and France but is not an exact match to any of them! the diamond shape is reminiscent of some French army insignia, as well as some wartime German ones, certainly think it is military and submarine or diver related? hopefully someone can give a definitive identification?

Regards

Tony