I'm sure that all of us have ended up pumping backside here and there out of necessity, but has anyone just went out on like a skateboard and tried to make their backside pump mimic their frontside pump (which is pretty much instinctive). Try to "throw" your arms like you do when frontside... it's pretty much awkward, but that should be obvious because your back is in the way so you can only throw your arms so much, but after a few minutes I finally got the technique down, so hopefully I can apply that to surfing because my backside isn't up to par with my frontside. Another observation is that my backside pumping muscles are also underused - after 10 or so minutes of practicing backside pumps on my skateboard my thighs were burning, while I can go frontside as far as my hearts intent. But after watching some videos online, I was encouraged to go out and practice techniques I could use while surfing, so that explains the existence of this thread. http://www.surfcoach.com/ check out the advanced tips, good stuff. Oh yeah, if anyone has any tips for backside pumping please share.
Try Costello's, lots of great advice there. Just walk up to anybody and ask for their help with your backside pumping. Should get lots of great tips.