The motor should be powerful enough, as pacifcmeister(creator of this forum) uses a simialar but slightly smaller motor (56104,500kv). You should look into his design, even if you build your own as he has a really good documentation.
I encurage everyone to share his progress, as even mistakes can be useful to understand the topic better.
One particularly useful graph about the power and thrust requirements for a custom desgin can be found on this forum: Board / Surfboard blanks - #4 by flyingchris - Foils & Boards - FOIL.zone
How did you build your surfboard?