Two hulls, one extraordinary vessel
A power catamaran is a twin-hulled motorboat in which two parallel hulls are joined by a bridgedeck structure. Unlike their sailing counterparts, power cats rely entirely on engine thrust — typically twin outboards or inboard diesels — to drive them across the water at speed.
The design traces its lineage to ancient Polynesian vessels, but the modern power cat emerged as a serious blue-water platform in the 1980s and has since matured into one of the most versatile vessel categories on the market, spanning everything from 30-foot weekend cruisers to 80-foot offshore expedition yachts.
The fundamental physics are elegant: by splitting displacement across two narrow hulls rather than one wide one, the catamaran reduces wetted surface area, slices through waves more cleanly, and achieves a dramatically wider beam-to-length ratio. The result is a vessel that is simultaneously faster, more fuel-efficient, and more stable than an equivalent monohull.
Whether you are crossing the Bahamas, island-hopping the Pacific, or day-running along a coastal waterway, a well-specified power catamaran offers a compelling combination of comfort, range, and seakeeping ability.
Key Terminology
- LOA— Length overall, stem to stern
- Beam (B)— Maximum width hull-to-hull
- Hull beam (b)— Width of a single hull
- Bridgedeck— Platform spanning both hulls
- Bridgedeck clearance— Height above waterline
- Draft (T)— Depth below waterline
- CLR— Centre of lateral resistance
- Displacement— Total loaded weight
- Tunnel— The space between the hulls
- Cross-beam— Structural member joining hulls
The case for the catamaran
Superior Stability
The wide beam eliminates the rolling motion inherent to monohulls. In beam seas, a power cat reduces roll angles by 40–60%, making offshore passages dramatically more comfortable and reducing fatigue on long passages.
Fuel Efficiency
Slender hulls pierce waves rather than climbing over them. At displacement speeds (8–14 knots), a power catamaran typically burns 30–50% less fuel than an equivalent-length monohull, dramatically extending range and reducing operating costs.
Living Space
The bridgedeck creates an expansive saloon platform impossible on a monohull. Split accommodation across two hulls delivers private cabins in each hull without compromising the social cockpit and salon areas above.
Shallow Draft
Two narrow keels draw far less water than a single deep monohull keel. Many power cats draft under 2 feet, opening access to shoal anchorages, tidal inlets, and Bahamian flats that are off-limits to deeper vessels.
Redundancy
Twin independent engines — one in each hull — provide true mechanical redundancy. An engine failure at sea is an inconvenience rather than an emergency; the vessel can return to port on the remaining engine.
Maneuverability
With engines at the extreme ends of the beam, differential thrust creates a powerful lever arm for tight-quarters maneuvering. Power cats can spin in place with no bow or stern thrusters required — invaluable in marinas.
Choosing the right platform
30–40 ft · Day + Weekend
Sport & Day Cruiser
Open-cockpit designs optimized for speed and simplicity. Twin outboards — typically 150–300 hp each — deliver planing performance above 30 knots with outstanding fuel economy at cruise. Ideal for coastal day runs, fishing, and protected-water cruising.
36–50 ft · Extended Cruising
Cruising Catamaran
The most popular segment. Enclosed saloon with galley, multiple staterooms across both hulls, and generous cockpit/flybridge for entertaining. Twin diesel inboards or large outboards. Designed for coastal and inter-island passages with self-sufficiency.
50–70 ft · Blue Water
Offshore Expedition
Full ocean-crossing capability, extended tankage (fuel and water), professional-grade electronics, and weathertight construction. Often features diesel-electric hybrid propulsion, stabilizer systems, and accommodation for extended liveaboard passages.
60–100 ft · Luxury Charter
Superyacht Catamaran
Bespoke builds combining the stability and efficiency of the catamaran platform with superyacht-grade interiors and engineering. Volume per dollar spent dramatically exceeds equivalent monohull yachts. A growing segment driven by electric and hybrid propulsion.
Naval Architecture
The science of the twin hull
The power catamaran’s efficiency stems from a single principle: wave-making resistance dominates hull drag at displacement speeds, and narrow hulls produce smaller waves. A catamaran’s hull-to-beam ratio (typically 8:1 to 12:1, versus 3:1 for a monohull) creates a slender entry that cleaves water with minimal energy expenditure. To learn more about the engineering involved with a catamaran view our Technical Information page.
