Rum sounds like your dad is one one those peeps who says something is good to justify money not wisely spent
![laugh.gif](http://www.fishingozstyle.com.au/forums/style_emoticons/default/laugh.gif)
just Joe King wit chu haven't seen the goat so cant really comment.
Going by what you've just said my guess is the 30 hp dosen't have power tilt & trim so thats why your dad fitted the tabs as far as making the goat gutless goes ??
I'm putting that down to Rum error ! tabs work & no different to to tilt on a motor if not correctly used what you described will occur by the sounds of things you have the tabs tilted to far up when you take off which in turn doesn't allow the prop to bite in hence the cavitation and gutlessness.
hustler if you picked up on what I just said to Chadd Chadd then you wont consider them
Outboards have their own tab system it's called power tilt & trim & they use the cavitation plate on top of the gearbox as the foil.
Fitting additional foils would create koas & there's no needfor them.
I've had them in the past actually made my ownbut they went onto the transom of my big moored goat which was shaft driven