Combined planing and foiling

I've made a model airboat which is designed to lift the bow from the water on a foil at high speed, and plane on what remains of the flat bottom hull aft. The model is made from an old boogie board and the transom area has been filled to give a sharp bottom edge to the transom. The foil is just a suitably bent aluminium strip with camber. There is no control of the foil so actually it planes at the water surface. It works! but I can't see any significant difference in speed between with and without foil.

Does anyone know of a real boat using this foiling (but really planing) forward and planing aft?
Could it increase the efficiency of a full size boat?

 

Seems like a stepped hull, but probably your foil has less drag at low speed than a step.

 

Yes, I have ridden in one.
It was made in Russia many years ago.
It was great in 1' chop.
Beyond that the waves would contact the raised hull at speed
causing it to come crashing down
creating huge drag and yaw to that side.
Eventually, a wave made its way through the front window landing on my lap.
The trip was aborted.

 

I'm aware of at least two "tail dragger" foil-assisted passenger craft. One fairly large one built with titanium forward foil and with transom intercepters at the stern; that entered ferry service for at least some period of time, in the Baltic if I recall correctly. Have not heard of it in a long time. The other was a craft built by Westport (WA) that was originally configured to be a fully flying hydrofoil but later modified to be a forward foil tail dragger.....I know the craft was tested to some extent in Hawaii but I don't think it ever entered service.

 

A forward foil (in line with the hull) creates a wave that the hull tail has to plane on. Since the wave-length depends on speed, the combo at best will have a very narrow "positive" operational window. The situation is different if the forward foil is mounted in the tunnel of a catamaran; there is still an influence on hull planing, but not as critical. But, as with most "engineering hybrids", the benefits seldom outweigh the drawbacks.

 

Thanks for the interesting replies, and now that I know what to search for I found a few (this link might be the one mentioned by BMcF)
Fast Passenger Foil-Assisted Monohull MF35 - Studio Arnaboldi http://studioarnaboldi.it/en/modelli/fast-passenger-foil-assisted-monohull-mf35/
I compared the fuel consumption figures for this vessel to my car and at the vessel's cruising speed it is more economical (per passenger mile) than my car with one person on board! (notwithstanding different fuel)