Light holograms are commonly created in glass and lucite using lasers(the easy way), or light and artistic genius by such as Frederick Hart.
Using underwater lasers, create underwater holographic sculptures
Installations can very from lake or ocean size masterpieces to the acquarium novelty gift-- theircompetitor, Dec 05 2005 Holography http://en.wikipedia.org/wiki/HolographyGeneral Description [csea, Jun 08 2007] LOOK FREE SQUID ---------> <bait+hook>-- Custardguts, Jun 08 2007 can you explain the theory behind this a little, I don't quite understand how it will create a hologram and not just a bunch of laser beams underwater. I like the idea if you can explain.-- bleh, Jun 08 2007 I once went to a Fish concert, and there were many lasers.-- CaptainClapper, Jun 08 2007 Holography relies on capturing and storing phase information between a reference beam and an image.
Where is the storage mechanism in your system? Glass and lucite work well, as they are (essentially) solid. I don't think fresh or salt water will do the job. --- csea, Jun 08 2007 Didn't the Irish do something like this in the Liffey in Dublin, with a digital clock, nicknamed "The Time in the Slime"?-- coprocephalous, Jun 08 2007 They did this in Loch Ness. It worked!
Seriously, though, won't the movement of the water distort the image?-- django, Jun 08 2007 a nice thing to go with a multimillionaires pool-- beanangel, Jun 30 2008 you'd have to make the holographs underwater too unless you want to put up with a hefty blue-shift.-- FlyingToaster, Jun 30 2008 random, halfbakery