Here is a a great video with proof of concept as well as great soundtrack (Weapon of Choice) and fun filmaking.
Engineering question, wouldn't we expect the fans to fail prematurely due to the increased resistance of moving oil rather than air?
http://www.pugetsystems.com/submerged.php
milo
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People say between two opposed opinions the truth lies in the middle. Not at all! Between them lies the problem, what is unseeable,eternally active life, contemplated in repose. Goethe