Cartesian Jetstream is a post-psychedelic band from the Isle of Man. They also reference post-punk.
You may find that hard to picture. There is amazing use of language, common in a lot of punk, but in this case it might make you think more of the Doors. However, it is not just unusual language, but is also full of religious references, both Christian and pagan, as well as references to folklore, including the title of the latest EP, More Songs About Lizards and Fairies.
In that way, they kind of feel like what The Waterboys would be like if they were psychedelic, plus if they were more sarcastic than earnest, because Cartesian Jetstream does not feel terribly serious. (And Mike Scott does.)
That being said, going by the music alone it feels more punk than psychedelic, and I say that while firmly believing that I heard a sitar on some of the tracks, including "Fit For Nothing". However, the first track on Sleep Over, "My Captain" feels like it was meant for dancing at the beach.
A lot of the psychedelia comes through more in the videos. They effectively use toys and costumes to create a mood. I don't know if raves are popular on the Isle of Man, but the horse and the bear both feel like they would fit in there.
I don't love the Christian references, which feel pretty flip, but it goes along with the hippie feel, and the music is good listening.