Surf's up Batman is a fun figure, but I suspect most people will display him holding the surfboard because the fin on the bottom of the board makes it impossible to pose standing on.

But there's a way to make it work.
Get some 6-sided dice, about 3-4 of them, all the same size. Place the dice on a flat surface, and the board on top of the dice to "float" it and the figure. You will probably have to fiddle with the arrangement of the dice to find the sweet spot to support the figure, and some poster putty to tack the dice to the board will help.
You can then pose Batman hangin' ten. Pshaaaaaw!

( This will also work with Surf's Up Joker as well)

I had him surfing in my display until I picked up the Surf's Up Joker. He was surfing on top of my Ho scale batmobile box. Now they are standing on my MIB Batmobile with their boards crossed.