A catamaran’s main feature is its two parallel hulls (floats) of equal size, connected by a frame or deck. They range from small recreational boats to large ocean-going vessels, and are known for their ability to sail at higher speeds than monohulls (single-hulled boats with heavy keels) due to reduced water resistance.
Sailing catamarans often have a large sail area, and their design allows them to harness the wind more efficiently. Power catamarans typically have two separate engines, one in each hull, providing very good deck space for fishing, and ferry services.
The interior layout is the major attraction and on a typical 40 footer, having two double cabins and a bathroom in each hull, plus a bridge deck saloon with panoramic views and a huge cockpit, very useful for the charter market and the leisure sailor, providing very comfortable cruising.
The Origin of Catamarans
Initially, it was a collection of fallen trees that were shaped and joined with vines to form a stable floating platform. The next evolutionary step was to tie two canoes together with a central seating platform. Ideal for the fisherman. Eventually, they built a mast, fitted sails, and constructed a small shelter, enabling boats to go further afield and cross large oceans.
The name catamaran is a Tamil word – Kattumaram. Kattu - bind together Maram - timber, wood, tree. The Tamil people initially used these boats to fish around the coasts of India.
The design covers the hulls and central deck area known as a bridge deck with a deckhouse or saloon and provides accommodation in the hulls.
Today, a catamaran provides extremely comfortable cruising under sail or motor. The saloon with panoramic views on the same level as the large cockpit hey area is ideal for entertaining.
One advantage as a sailing boat is that it does not need ballast in the hulls; this makes a sailing catamaran light and fast. The catamaran has an engine in each hull, giving the boat exceptional manoeuvring ability. The interior layout on an average 40 ft cat is four double cabins. Two double cabins and a central bathroom in each hull. Ideal for the leisure market.
In the 1870’s Nathaneal Herreshoff, the designer of many America’s Cup Boats and famous boats of the time, designed and built a range of fast racing catamarans that were ahead of their day and didn’t go down at all well with the racing traditionalists, racing and consequently building ceased.
Key Differences - Between a Yacht & Catamaran
Catamarans are known for their stability due to their wide hulls, while a monohull yacht can heel or tilt more.
Catamarans are often faster than monohull yachts of the same size because of reduced hull resistance, and in comparison, they are much lighter boats and do not need a weighty keel.
Catamarans generally offer more interior and deck space, making them suitable for larger groups and the charter market.
Catamarans are more expensive than monohull yachts of similar size due to their advanced design and features.
Choosing between a yacht and a catamaran depends on your preferences, intended use, and budget. Yachts are traditional and luxurious, while catamarans are modern, stable, and spacious, making them suitable for various activities on the water.
None-Destructive Testing (NDT)
The None-Destructive Testing (NDT) technique is a very good tool for inspecting spars and standing rigging connections for hairline cracks. The Ultra-Sound is very effective but needs training to understand the kit and resulting data, the Dye Penetrant system below is much easier to use.
The Dye Penetrant Crack Detection System comprises three aerosol sprays, a cleaner, the dye, and a developer. Follow instructions carefully and photograph the results; cracks will show as a distinctive red line. Ideal for checking cracks in solid stainless-steel rigging, chain plates and toggles, masts and booms where there could be stress-related cracks behind tangs, spreader roots, and connections, ideal for testing the area around the foot of the mast.
PTFE – Spray Lubricant
PTFE spray is ideal for sheaves, cars and travellers, winches (not the greased areas), furling gear etc. it does not absorb dirt and dust and is suited to the sailing environment.
Modern Diesel Engines
To reduce harmful emissions from Diesel engines the search for cleaner emissions has resulted in engine manufacturers redesigning fuel delivery systems. Common rail diesel delivery is one system. Injector pressures in the '70s were around 300 bar (4,351 psi); today, pressures exceed 2,500 bar (29,000 psi); this higher injection pressure is a key factor in reducing an engine's untreated emissions. It also improves atomisation by having a better fuel-air mixture ratio, meaning optimum combustion is achievable, giving enhanced power output and efficiency.
Diesel Fuel-Sulphur Content
The sulphur content of diesel fuel over the last few years has reduced from 500 parts per million to 15 ppm. This fuel is now known as ULSD (ultra-low sulphur diesel). This dramatic reduction has resulted in problems for manufacturers and operators of diesel engines and diesel fuel distributors.
Modern engines have a higher power-to-weight ratio and are more reliable and cleaner than older engines. Many now have electronic controls to optimise fuel consumption and efficiency. .
The maintenance of catamarans is described fully in the main section. Click here to find out more.