I would take the .."Airboat", ANY DAY over a hovercraft. Look at the hovercraft videos; They slip and slide and can hardly make a corner...blowing water everywhere. It also seems you have to "Ride" the hovercraft on your toes.. standing up..to maintain balance and control.
The "Airboat" will skim the ice..AND... bank in a turn on the water. I like the "Airboat" consept for Water AND Ice use.
NB