How should I attach Sharpedo's fin? (Foam+Cardboard to hat)

[Sanabun]

Hello! For AX this year I wanted to do a casual Sharpedo gijinka cosplay and this is the sketch of what I plan to do:


I'm having trouble figuring out what is the best way to attach the top fin to the snapback that I will be buying. I will be making the fin out of craft foam and cardboard.

Thank you for the help!

[penlowe]

Use a peg or screw up through the mesh at the top of the hat into the fin. Glue in place.