Ah, thank you! Sorry, should've thought about that. In any case, got another one:
http://i.cubeupload.com/1WvDt2.png http://i.cubeupload.com/0UyBgT.png http://i.cubeupload.com/UM7AN3.png
When you try to surf in that specific spot, the tree appears to block the way and this is what happens. I don't know if this is something that should be fixed on an engine-level or simply an oversight in this specific part of the level, but well, there you go. The game appears to behave relatively normally otherwise, when walking on grass water-borne pokemons show up, and this does not seem to