No, water really isn't fuel storage. If you're at the destination where you want to use hydrogen for fuel, and you also have at your destination the electricity needed to split it, you can just use the electricity. No need to turn it into hydrogen and then burn the hydrogen.
Except if you need a form of energy that you can distributed at a location, have abundant electricity and water at a specific point at that location, and don't have infrastructure to efficiently move electricity around. But yeah, transporting water itself probably isn't smart.
