I cut it out of my edit, but when they are swinging and clash in midair, can Anakin lose his saber? They are swinging far enough out it may be believable that it lands on the shoreline. It would need some digital work to paint out his blade, and potentially put a saber in falling to the ground, which Obi-wan would then pick up when he gets to shore. That would be the easy way out if anybody here is able to do that