There's a lot of really great moments in this episode, but I'd like to highlight the brief exchange between Campion and Kehaar.
I really appreciate that Kehaar, despite generally being comic relief, is shown to be perceptive and concerned about Campion's state of being here. I like the blink-and-you-miss-it look he has when Campion tells him that he "feels like an alien in his own warren." It's a very small thing, but it gives me the impression that Kehaar is empathizing, being both the only gull on Watership Down and having recently gone back to the big water to find that he doesn't quite fit in with his old friends either. They're an odd match-up of characters, definitely, but I think mixing Kehaar's energy and Campion's stoicism could have made for some more great moments like these.
The only thing I would have changed would be to have Kehaar actually describe the big water properly. I didn't find the joke made with Kehaar's stumbling all that funny and it would have been a really nice moment for both of the characters to engage in a bit of blissful escapism together.