This will keep splashes and sand off the camera, but the centre of the glass fogs up right from the off, rendering it useless for taking pictures. A pity because the basic design is good, and all the controls work as they should. It is not strong, so not suitable for water-sports, and there is no protection for the lens. Sony equivalents have a built in lens hood that ensures that the glass does not get scratched.
While I am aware that you only get what you pay for, the inability to take fog-free pictures means that I will be returning it to Canon as unfit for purpose (it is not the seller's problem, the design is flawed IMO).