A few thoughts if I may from a layman's perspective. Interesting concept, although I would think the faster you go the more air lift realized through the underside of the hull will equal less disturbance on the water surface so less chance of water getting kicked up into the vents. The idea of the vent covers could greatly assist at lower speeds but when even partially opened at higher speeds I would think the force behind the water being forced up into the vent will be minimally controlled no matter what you do. With the prop thrust causing a vacuum effect on the air from and over the vents it will inevitably bring the water along with it and if the foils are as I suspect the air flow at the trailing edge of the vent will be moving faster than the air flow above the vent in a disturbed upward direction and dragged into the prop wash. With an air engine there will be a ram air effect in and over the vents whereas the Miss Bud in the video the air flow is controlled passively I believe. I realize there is so many factors involved and the placement of the engine in relation to the vents and the overall aerodynamic properties are key to the success or failure is near impossible to assess from a keyboard and none the less intriguing to see how it all comes together. One thing I am certain of this is beyond my experience level and you are certainly challenging yourself with this one
