If that were on a racing car we'd say that you'd gotten the engineering just about right 
One more layer of carbon and you'd have been golden...
Very impressed 
the fin looked awesome pre-breakage but least you are setting up some numbers for future models to make them stronger and ironing out any faults, keep up the good work.
All good designers make many designs that let go so it helps with the design process.Nice turn around on MK11 by the way.
Thanks for the reply. I've decided it's going to make a great 38cm weedie for my 7.2m and 115 rocket.
Just reinforced the base and mid length, after taking it right back, with 10 strands of uni and put a layer along the chord.
