Plane / Planes / Aircraft / Aeroplane / Airplane appreciation

The immediate problem I can see is the fixed wing will not tolerate freak waves / pitch / troughs like a bird would. I realise scale is relative but a dragged wing is a dead crew.

The concept pictures show extremely low altitude, but useful ground effect starts when the altitude is approximately equal to the wing span, so the Pelican could fly at 500' and still be getting some benefit. Dropping to quarter span, 125', only puts you in the way of the very worst of rogue waves. I would expect a large part of the research on the Pelican project was devoted to dealing with the effect of water waves, since any wave which was a significant proportion of the flying altitude would change the lift, causing a rough ride.