I'm sure this has been discussed but what is the ideal paddle height for someone that sup surfs.... high performance surfing.

Thanks!

Most people , head height ,because I'm using small blades ,I tend to have mine 25 ml or 1 inch above my head ,it just seems to work for me ,I use it for flat water as well on my 140 .what volume is on your board that you surf ? mine are 126 & 130 ,@ 98 kgs ,
I surf my 133 SPX and straight away my paddle feels short .if you can cut it ,then just tape it up go for a surf ,see how it feels .then shorten a bit later ,Thats how I found my sweet spot .if you are a surfer that has your board fully submerged then it will be shorter .

Just start with exactly your height.
That's the base length that works for all.

You can then try to shorten it later (for surfing more aggressively, on hollower waves, on shorter boards...) or a tad longer (for longboard surfing on mellow open face waves?).

But you should first spend some months at your height to get comfortable with it, your technique will adapt.
You can then borrow an adjustable paddle to test other lengths.

It depends on the guild factor of your board and your personal preferences. Exactly your height is a good place to start, as stated above. My usual boards guild factors range from 1.19 to 1.12 (assuming I am still 105 kgs and haven't gained too much weight recently). My paddle reaches my nose and I am happy with that on those boards. The higher the board is out of the water, the longer the paddle should be and vice versa. I used my older two piece adjustable paddle to find the perfect spot before I committed to a one piece fixed.

This could be wrong, but I believe that if your shoulders hurt, then the paddle is too long. If your lower back hurts, then the paddle is too short.

Eyebrow height for me on shorter boards

Mine maybe 1" less than head high and I worked down slowly from 2" above head, 1.1-1.2GF. I'd go more but afraid to cut paddle and regret it. 82 paddle blade