[Zeisen]

I tried verify FL_ONGROUND client flag but it doesn't solve.

[backwards]

it really depends on the instance you want. do you want to check only while they are on the ramp? if they go in the air in between you can assume they are still surfing if they have high velocity and haven't touched the ground yet. You'd most likely want to check for higher velocity and then do a raytrace straight down below the player and get the surface plane normal and compare if it's a possible surfable or not.

[hmmmmm]

If you wanna check if they're currently on a surf ramp, you can do a trace hull and check the plane normal. IIRC for a plane to be surfable, the normal z has to be <= 0.7

[Franc1sco]

Originally Posted by hmmmmm IIRC for a plane to be surfable, the normal z has to be <= 0.7

Exactly, here a example.