I dropped a GoPro into the depths of the sea. I had it attached to a 60 meter long nylon fishing line, just in case. At about 40 meters it hit the bottom. Next time I'm in Greece I'll swim a bit further into the sea and I'll do so early in the morning, it probably looks better when the sun is not as high up in the sky.
And the children's security thing you see at the beginning of the movie? I used that for two reasons. First so I am visible, I swam all the way out, probably a mile or so, in a pretty touristy area. I don't want to get hit by a jetski. And I needed something to keep the GoPro afloat while swimming. Next year I'll try to find something that looks a bit more cool.
This was shot in Greece in the see outside Chanioti in Chalkidiki. A hundred meters or so into Ta Mavra – vimeo.com/48479645/