Ultra light displacement boat
An Ultra Light Displacement Boat (or ULDB) is a term used to refer to a modern form of sailboat watercraft with limited displacement relative to the hull size (waterline length). Principally manufactured from the mid 1970s through mid 1980s, these boats generally sit higher in the water allowing them to move faster in nearly all water types other than directly crashing into larger waves, upwind, where the momentum of the water slows the boat down due to their lighter weights.
Source: Wikipedia — Ultra light displacement boat (CC BY-SA 4.0)