Wiktionary
ice scooter
n. A type of ice yacht equipped with runners, a flat bottom, and is capable of floating in the water which makes it safe to use also on thin ice.
Wikipedia
Ice Scooter
An Ice Scooter, also marketed as an Ice Skeeter is a machine similar to a snowmobile which can be used on ice. It was sold and marketed by Sears Roebuck Corporation and other companies.