Dapple sees where you're pointing and turns around to explain, her nude body framed against a void backdrop of vastly distant huge pink leaves.
"Oh, that? That's the Lightbreeder guildmark. Someone probably put it there to remind anyone going this way not to damage the Shine Jelly Hives."
Dapple puts her hands on her hips.
"So! There are three main principles of tree-surfing."
"Number one! The greater your speed, the more stable your footing. Stay on the moss, and go fast. The moss likes to grow on concave curves, so it'll be thickest on the most efficient line, but that's a bit advanced so don't worry about it. Also, the moss will take all of the heat from friction into itself, so if it feels hot, that's because someone else was there before you. That can help you navigate sometimes if you get lost."
"Number two! Lead with your left foot, and Always. Dodge. Right. On well-traveled courses, you might run into someone surfing in the opposite direction! If you both dodge to the right, nobody collides. That's the easy one."
"Number three! Most of your momentum will come from gravity-shifting, but, gravity-shifting has several very important limitations you have to keep in mind. First, you can't adjust a gravity-shift after it's created. Second, they're always static relative to the frame of reference you use to create one, and can't be moved. Third, you need a strong frame of reference to create one. You must convince your brain that your environment is oriented in a given direction, that a given landmark is above or below you, before you can create a gravity-shift. Fourth, you have to snap your Numinosity back to yourself while you're still inside or you'll lose the Numinosity permanently; that's easier than it sounds, you'll do it instinctively when you cross the threshold unless you're trying not to. Fifth, you can't gravity-shift where there is already consensus gravity."
Dapple pauses.
"I think that covers the basics? Oh wait. The size of a gravity shift is determined by the distance between you and the landmark you orient on, it will fill the space between you and that landmark in a sphere. You can control the shape a little bit with intent, but not the size. Also, the bigger you make a gravity shift, the more time it takes to pull your Numinosity all the way back to where you can use it again. Fractions of a second for dozens of feet, minutes for miles."
Dapple gives you an apologetic, slightly sheepish smile. "You're not Numinous enough to gravity-shift yet, so you'll have to ride my wake. And don't worry about falling. Natural gravity is quite weak out here this time of year so you should mostly stay on course even if you do fall. And if you do, I promise I'll catch you."