Do the cases really float?
In almost all instances yes. The Aquaclip creates a hermetic seal – once closed the case is airtight. Most electronic equipment is full of air. So it’s not so much the air round the outside of your phone or camera or whatever, but the air actually inside it that makes it float.
If you put lead bars or gold ingots inside a case and carefully squeeze out all the air before sealing, the Aquapac may not float. Sorry.
NOTE: Please test your individual case with contents to check if it will float