Sounds like a Sizzler. I worked for the factory in Ohio. That bow "foil" you are talking about was supposed to do exactly what you described -- keep the boat from pitchpoling. I think that others did not adopt it because everyone said, "Yeah, well, it brings the bows back at a certain angle of attack, but if the bows were to go down at a greater angle of attack, the bow foil would actually tend to take it on down instead of bring it back up." (We didn't do enough on-water testing to learn the answer.)

The designer of the boat and the bow foil was Carl Swenson, and I'm sure he has long since departed this world.

He also invented some lifting foils for the hulls (sort of like butterfly wings) that clamped onto the forward part of the bottoms of the hulls. People said the same thing about them -- would give lift until the boat exceeded a certain degree of forward pitch, and then disaster.

But that was long ago and he was doing early experimentation.