DenverRalphy wrote: »It because that small patch of shallow water is inside the WB's arena just next to it. Not all WB arenas are like that (no idea why some are), but you'll be dismounted anywhere within the radius of where the boss spawns regardless from which side you approach.
The fact that you happen to be in water where it happened to you is just a coincidence. If you ride up the footpath on land towards the arena you'll be dismounted as well.

SilverBride wrote: »@Gabriel_H Thanks for the explanation. It just doesn't make sense to me why they would mark this thin little spot this way. The only time I use this route is when I've recalled to the house to get to a survey that is nearby. I'll try to avoid it next time, or not mount up until I'm past it. But it would be nice if they fixed this.
I could have sworn I've ridden close to other world bosses without dismounting before.