Apple iWatch has taken the physical shape and has been announced yet it is still in the stages of evolution and development. It is yet not available to the users and you will have to wait till next year that you will be able to wear it. The company is still trying to add more and more in to it. We cannot say with conformity that how long the battery will last or is it really water proof?
At least Apple has not confirmed it in ether manner. However Apple iWatch will be water resistant and can endure rain and you can conveniently wash your hand while wearing it. It does not mean that you give it a rough treatment and go to the swimming pool while wearing it; you cannot have a shower either while wearing it. It is water resistant and not the water proof in real sense.
Apple has released pictures on the hands of some athletes and shown it while they are washing their hands. Probably it means it is good enough in water resistant to some extent in daily life and it is not designed to remain under water at the depth of 1 meter or you swim with it in the swimming pool.
The image shows its durability to some extent and does not mean a complete water proof iWatch.