Navigating the Waters: Choosing Between Inboard and Outboard Boat Engines

inboard and outboard boat engines

In the world of boating, the choice between inboard and outboard boat engines is a pivotal decision. If you are buying a custom-made RIB, you will want to think about the positioning of the engine, as it will impact the look and feel of the RIB.

We are often asked what the difference is between the two types of engines and the benefits of each. We have written a short comparison of inboard engines and outboard engines.

inboard engine

Inboard Engine

Inboard engines, also known as inboard motors, are a type of propulsion system that is installed inside the hull of the RIB.

Advantages of Inboard Engines

There are several advantages to having this type of engine on your yacht tender.

  • • These engines are mounted inside the hull of the boat, which results in quieter and smoother operation compared to outboard engines. This feature is often a consideration when designing a luxury boat.
  • • Inboard engines contribute to a balanced weight distribution within the boat, which enhances stability and helps the boat handle well in various sea conditions.
  • • The absence of an exposed engine on the transom can result in a cleaner and more aesthetically pleasing look for the boat.

Disadvantages of an Inboard Engine

While offering several advantages, inboard engines also have some disadvantages that should be considered.

  • • They are typically located within the hull, which can make routine maintenance and repairs more challenging and time-consuming.
  • • While inboard engines can provide better weight distribution, they can also add weight to the stern of the boat, potentially affecting the boat's trim and performance.
  • • Inboard engines can produce propeller noise and vibrations that may be transmitted through the hull, affecting comfort on board.
  • • Inboard engines are less suitable for boats that need to operate in very shallow waters due to their draft and submerged propellers.

outboard engine

Outboard Engines

Outboard engines are a type of propulsion system that is mounted on the exterior of the boat, typically on the transom at the rear.

Advantages of Outboard Engines

  • • Outboard engines have a number of advantages that make them a popular choice for leisure boating.
  • • Outboard engines are located on the boat's transom, providing easy access for routine maintenance and repairs.
  • • These engines are designed to be easily removed from the boat, reduce the risk of theft and are easier to store during winter.
  • • Many newer outboard engines are designed to meet or exceed environmental regulations, emitting fewer pollutants into the water and air.
  • • Outboard engines often start quickly and easily, making them convenient for spontaneous trips on the water. 

Disadvantages of Outboard Engines

Despite having many advantages, outboard engines also have a few disadvantages.

  • • Outboard engines add weight to the boat's transom, potentially affecting trim and performance, especially in rough water conditions.
  • • The outboard engine's propeller is exposed and poses a risk to people in the water. Safety precautions are necessary when swimming or getting in and out of the boat.
  • • Some outboard engines can generate more noise and vibration, which may affect onboard comfort and experience, particularly in smaller boats.

Choosing an outboard or inboard engine is a personal preference, and each has its set of pros and cons. While inboard engines are out of sight and, therefore, may be more visually appealing, they are not always suitable for shallow waters.

Meanwhile, outboard engines are quick and easy to start, they may impact the comfort of the RIB when in use.

Contact our team to learn more about each engine type and discuss which might be better for your needs. Call us on 01202 612 712  or email us at