Maybe you could repair a whole lot of tears with a roll of drywall fibreglass tape and a big tube of neoprene glue
- put the sticky tape over the tear
- then cover in neoprene glue
- repeat on the other side
go foiling again
My two favorite repair tapes can do just about everything
Dacron Sail repair tape for wing canopy and leading edge repairs
www.westmarine.com/bainbridge-dacron-sail-repair-tape-P002_068_002_503.html
Tear Aid Type A for bladder repair and it works great to seal up board dings
www.tear-aid.com/
Always clean up surfaces really well with rubbing alcohol, and mild heat from a heat gun makes the tape adhere much better.
I use Gorilla duck tape. I've used on a ton of repairs. Holds up over time.
Next time try and round the corners of the tape off. There is less chance of the corners catching and the tape start peeling off.
Gorilla Tape may be a challenge for rounding the corners. It might be the one tape that doesn't need rounding off.