Where is the foil turbulence?

Takuma switching from bottom to top tail has me thinking about where the turbulence is relative to the tail. This photo makes me think it must project well under the tail. After all, old takuma used to be bottom mount, WITH the fuse angled down, if that doesn’t run into it idk what would?

Reminds me of this pic from this forum though expect a salty reply if you ask them anything.

This was a pretty informative post, and this one. Seemingly it matters more at higher angle of attack at which point lower is better to avoid deep stall, which might still apply with foils? Maybe hydrodynamics changes all of it anyway.

Back of the napkin analysis I’d guess it is probably a trivial improvement. Maybe fair to say from the first image that in theory a top mount might be better, but stalls become more severe.

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I don’t know about the turbulence, but the designer of the Kujira foils talks about stabilizer position in this video, he tried different heights from -30mm to 40mm in 5mm increments and ended up putting it in line with the front wing for more glide and stability. He mentioned raising it makes the ride more surfy (it would be fun to try that). AFS SILK - Le foil ultime de wave riding - YouTube

Takuma’s decision to top mount the stabilizer may have more to do with compatibility with their foil assist fuselage than for any reason related to foil performance.

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Top mount also has the advantage of not banging your stabilizer on the rocks as easily

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