There was a shot of an X-Wing under the water. And when Luke showed up at the end to fight Kylo Ren. I had thought he pulled the X-Wing from the water and flew it there. But of course we learned it was just a force projection or something. Though this whole force projection thing is pretty lame. It’s just a way to get Kylo and Rey to interact without using a telephone or something.
You’re forgetting that Vader was in thought communication with Luke at the end of ESB. ROTJ would have had a similar scene, but it was cut. The way Rey and Kylo were communicating was new even to him. And Kylo wasn’t able to see much beyond Rey. I doubt either could interact with the other’s surroundings.