A catamaran is a watercraft with two parallel hulls of equal size. The wide distance between a catamaran's hulls imparts stability through resistance to rolling and overturning; no ballast is required
The Spirit of Dallas catamaran on White Rock Lake
A Formula 16 beachable catamaran
Powered catamaran passenger ferry at Salem, Massachusetts, United States
1827 depiction of Tahitian pahi war-canoes
A pontoon boat is a flattish boat that relies on floats to remain buoyant. These pontoons contain much reserve buoyancy and allow designers to create large deck plans fitted with a variety of accommod
Catamaran
…Multihull Pontoon boat Marchaj, C. A. (2000). Aero-Hydrodynamics of Sailing. Tiller Publishing. ISBN 1-888671-18-1…
A pleasure boat with two lengthwise pontoons
A pontoon ferry crossing the Zambezi at Kazungula
Odyssey Cruises jumbo pontoon boat