I could see i had a huge cavitation going on while foiling, especially at higher speed so i tried filming it with my 360 cam. Interestingly enough it comes from the old cable inlet which i’ve just taped over to cover it (a few layers though).
Clearly there’s a low pressure area created on this small irregularity - i never thought it could give this large effect!
Time to fix properly 
Interesting video, must have been challenging to foil and shoot at same time. I’d have face planted for sure 
All of that from a small hole that’s sealed! Do you think the tape bulges out or sucks in to create the irregularity? Perhaps doesn’t make any difference which.
Makes me wonder what a duct, nosecone etc if it wasn’t perfect would create.
How fast were you going when you did video?
I don’t know but not super fast, 25-30kph is what i’d assume.
How large is the inlet? I assume the tape is getting pressed in under pressure and then creates the cavitation.
What made you move the motor higher up?
I run a flite motor setup nowadays so the motor is at the wing.