So...

Does this one float your boat? Sorry couldn't resist ;)

 

No Photoshop (well except for the usual resize, sharpen, border), this is a real life optical illusion.

 

We perceive the boat to float above the surface of the water because our brains see the shadow and assume that it's on the surface of the water, so we think that the boat must be floating above the surface. In reality of course the shadow is on the seabed; the only reason we can see it is that it's a sunny day, the water's clear, and the sea bottom is quite pale. This type of illusion is known as a cognitive illusion, as it relies on the way the brain processes information to work.

 

The water colour has been enhanced by the polarizing filter, which also cuts any reflection that might give our brains a clue that things aren't quite as they appear. The water really is a wonderful turquoise/cerulean colour though; I suspect it's caused by fine particulates in the water, as the water changes back to a more normal blue colour once it leaves the bay itself.

 

This shot was taken near the Minack Theatre on the Cornish coast at Porthcurno

 

Canon EOS 400D DIGITAL

Canon EF 300mm f4/L IS

f4.5 @ 1/350 ISO100. RAW converted via DPP.

Done