The catamaran’s design reduces the waves and wind’s effects, allowing the boat to travel farther and faster compared to monohulls of comparable sizes.
However, the wind and waves are unpredictable, so catamarans use motors as either backup or the main propulsion based on their construction.
In this article, we provide all the answers concerning questions about the propulsion systems available to catamarans:
Do Catamarans Have Motors?
Catamarans, including power and sail types, have motors and other mechanized propulsion systems. Except for small cats used in coastal waters, most large catamarans come with different engine combinations even if they have sails.
Do Catamarans Have One or Two Motors?
Catamarans can have two engines because they have two hulls.
This makes them highly maneuverable while underway and makes handling in shallow and tight waters a breeze.
However, many large cats use only one engine. With two engines, you have more maneuverability over the boat, but one engine may increase the speed and fuel efficiency since it reduces weight.
One of the best combinations in a cat is to pair two engines with counter-rotating propellers. The level of control this configuration provides in the water, especially at the marina, is mind-blowing.
Whether you are backing up or mooring, you can adjust the two engines independently to achieve many of the things monohulls find difficult.
So, what propulsion systems are available to catamarans?
Whether you are looking to buy a power cat or sail cat, both feature engines. There is a wide range of power options for different uses based on your budget, preference, and craft design.
8 Types of Motors Used in Catamarans:
1) Single Outboard
You will find this in small-sized catamarans of about 25 feet and below.
While single outboards cut cost and weigh less, they can be difficult to steer under power except when you use the motor to turn.
This is because the motor needs the water to flow over the rudders to turn the boat.
Except for owning a small catamaran, a single outboard is not the most efficient propulsion system for this watercraft.
2) Two Outboards
Like monohulls, you can use two outboards on a catamaran.
Smaller cats such as the Seawind 1000 and Gemini 32 can be fitted with two outboards for improved maneuverability in tight quarters and redundancy.
This setup is great for small cruising catamarans because it is far lighter than two large diesel engines, allowing you to store more essentials on the boat.
Catamarans may be faster than monohulls, but their speed decreases with the load they have to bear, so cat owners try to keep their boats as light as possible. Another benefit of this configuration is that two outboards are more affordable compared to diesel engines.
Plus, you can run on one engine if one dies on you while on the water.
However, this arrangement has some serious shortcomings.
Outboards are not the best means of propulsion on the open seas. Because of their inherent weakness, outboards don’t last long, and their reliability decreases with increased exposure to the harsh saltwater environment.
The design of outboards makes them less suitable for choppy waters.
While you can use outboards in twin configurations for catamarans, they perform best on smaller monohull watercraft.
3) Single Diesel
This is common in custom catamarans.
It comprises a single diesel engine in one hull, which reduces weight and makes it more affordable.
However, this configuration can make turning in tight quarters almost nightmarish except for highly skilled skippers.
The boat will turn easily to the side opposite the engine location. For example, the boat will turn with little starboard issues if the engine is in the port hull.
However, you may require several boat lengths to maneuver it to port.
For best results, plan your turns well in advance and do a lot of practice to perfect docking in tight quarters to avoid costly mistakes.
4) Single Diesel Engine with Retractable External Drive
This combination is popular with Prout catamarans, using a Sonic Drive-by Sillette.
It comprises a cockpit diesel engine paired with a steerable external motor.
The arrangement reduces weight and does not create drag when the drive leg is out of the water.
However, the reverse lock mechanism may not work sometimes. Also, the steering yoke and bellows may not work properly when you need them.
This setup is best for smaller boats where two engines’ thrust will be overkill, and they help to save cost and weight.
If your catamaran is on the heavier side, you want to go for something sturdier and more powerful.
A 32 feet Gemini catamaran will make an excellent candidate for this arrangement as the boat can use a single-engine with no problems.
5) Diesel with an Outboard
People who use this configuration do so to save cost and counterbalance the single diesel engine’s powerful thrust.
The auxiliary could be smaller petrol or electric-powered outboard motor.
When you are on the open seas, the diesel gives you enough propulsion during calm weather when you can’t use the sails. The outboard helps in shallow waters, although it is often useless on the high seas, especially during turbulent weather.
The smaller outboard also provides less turning power when it’s very windy than running two powerful diesel engines.
You save space, reduce weight, and keep a few extra thousands of dollars in your bank account.
6) Twin Diesel Engines
For larger catamarans, especially cruising types capable of transatlantic and transpacific voyages, the standard propulsion comes from two large diesel engines.
Each engine is housed in one hull, providing exceptional longevity, fuel economy, and incredible amounts of horsepower to help you through the rough seas in the shortest time possible.
This combination is excellent for redundancy, even though most catamarans can run efficiently on one engine most of the time.
The downside of having two diesel engines is weight, cost, and maintenance.
Diesel engines, compelling models that produce upwards of 40-45 horsepower, can set you back by tens of thousands of dollars. But they will deliver over 8000 hours of work-life easily.
In terms of reliability, durability, longevity, and performance, nothing trumps diesel engines in the marine industry.
Diesel engines are safer to operate as they do not have the same explosion and fire danger as petrol or gas engines. They are easier to maintain and simpler to operate.
Plus, they are the most mature propulsion system in the seafaring world.
However, diesel engines are also heavier and will take up more hull space.
That means less space to store your gear, but it’s a worthy sacrifice considering the capabilities diesel engines offer your boat. Diesel boats not only drive your propeller but can also provide the energy to run every electrical system on board, including navigational equipment, cooking, air conditioning, entertainment, among others.
7) Hydraulic Propulsion
Some catamarans use hydraulic propulsion systems, although these are not popular.
Hydraulic systems are better suited to terrestrial applications as they are prone to many problems that can complicate matters for you while underway:
- One, hydraulics generate additional heat, which makes them inefficient.
- Second, they can be uncomfortably noisy, making socialization difficult and defeating the whole purpose of leaving city life’s buzz.
- Third, hydraulic systems are prone to leakages, which increase their running cost and harm the environment.
These factors make hydraulics less efficient compared to diesel and petrol engines.
8) Electric Hybrid Systems
This propulsion system comprises a diesel engine and an electric motor.
The main issue with this configuration is the complexity of the systems and their overall lower efficiency.
Other Propulsion Systems:
As technology advances, sailors and marine engineering experts continue to find new and better ways to improve seafaring while reducing the planet’s carbon footprint.
This has led to solar, wind turbine, water, and pure electric motor propulsion systems.
For example, the Solarwave Sailor 64 is a solar hybrid-powered catamaran with an installed capacity to generate 15KW, enough to power everything on board the boat.
Solar and electric systems are silent and clean. However, they are insanely expensive and not as reliable as diesel and petrol engines. Also, they require banks of batteries, which add a lot of weight to the cat.
Catamarans may look out of place, but many of these vessels offer more flexibility regarding power options.
You can choose from outboards, inboard diesel engines, and even go for the newer electric or solar-powered models.
However, the diesel engine remains the best power system available today for catamarans and other boats.
For reliable performance and mind-blowing thrust capabilities, experienced sailors depend on the time-tested diesel engine.
Morten is the founder of GoDownsize. He has filmed and interviewed people living in tiny houses and RVs since 2011. He grew up on the coast where his dad took him boating from a young age. He has completely rebuilt two RVs in which he travels with his family for months at the time. Read more about Morten here.