Arrow,
I suffered from the tail bob when the mH head went flying....ironed it down to my pet peeve...too much friction in the head linkages....particularly the short pitch control links.
Those links go through the greatest angular swing and they're still giving me fits.......thinks: wonder if increasing the flybar paddle areas would help....don't know how but just an idea.
Barrick...welcome back to the Darkside....didja take photos....? Some neat hydrofoils out there.

R