+1 on that!
A lot of people forget the importance of their beginning position on the board while beginners...they either try and stand up too far forward or too far back....either one will throw you off as you try and pop-up to a stand. Tape on the board where your nose should be works. I have a friend who painted two spots of bright red where his feet should go during the pop-up. It worked ! After he got the idea ingrained, he just took the cheap paint off with a lot of rubbing with "Goo Gone".
Having a friend watch your position on your board as you're popping up is excellent too. Even more helpful would be to have someone with a waterproof camera case take video from close range (from the side) as you are popping up, that way you can see for yourself what you're doing wrong....AND right!
Board balance during the pop-up is the single biggest factor while learning...the board seems so stable and robust when your lugging it on the beach...but once you're on the water, you find it's slippery and squirrely and wants to wig out on you with every false move. That's because you haven't got the momentum from the wave yet....once you ARE up and the momentum takes over, it becomes stable and a longboard you can ride it right to the shore! And YEAH...you'll have a tendency to try and knee board it on the wave, as it's so much easier. Start out right and try and fight that tendency.
So focus on your foot position and centering your mass as you pop-up...and get someone to video you as you pop-up.
Have fun!!
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