Hi guys, I need help. I want to buy a Fanatic Stylemaster 10' and am unsure whether I should go for the 28.5" or the 30.5" version. I have been a longboard surfer for 25 years and am doing quite well, I'd say. I have never used a surf SUP, though, this will be my first. I am 49 years old, 1,80m and weigh 80kg. What would you consider the better version of the Stylemaster for me? Thanks!

I'd be looking at the 28.5 inch version personally. You might find it a little hard at first but with 25 years surf experience you'd be wishing you had the 28.5 if you went with the 30

Yep for sure Plotzy.
if you've been surfing that long - it won't take you long to get the groove on a 28.5 board.
As Nug says, you'll be wishing you went narrow before long.
My first SUP longboard was a 10'6 x 32" Style which I sold to go narrower and shorter.
Save yourself the hassle and get it right for the start I reckon.

Can you try one or the other first?
I'm lighter, have the 30" Fly, and it is not stable for paddling, and easily drives into funboard bottom turns and otl's.
Do over, I'd get the wider, shorter wave SUP.

Go with the 28.5 Stylemaster. They are very stable boards with a ton of paddle speed out the back and I think if you get the bigger board you will sacrifice performance for stability that you don't really need. I am 8kg heavier and a few cm taller than you. I have a fair amount of experience with the first gen 10' Stylemaster. It is 30" wide and 135ltrs and if I was replacing it I would definitely pick the smaller version.

Thank you all for your answers! So I've decided to go with the 28.5 - wish me luck to make it out to the line-up :)

Good luck.
Maybe adopt an offset almost half surf stance for side to side stability.
A smaller blade paddle can add rpm and stability also.