Thurster Sizing

For optimal maneuverability, it is crucial to have a thruster selection chart specifically designed to deliver sufficient thrust under all operating conditions. While any thruster can provide some effect on board, selecting the right thruster is key.

Many boats nowadays come equipped with factory-standard thrusters that generally meet the requirements of most customers in normal conditions. However, for skippers who navigate in more challenging conditions, it might be prudent to consider a more powerful thruster. In such cases, most boat builders offer thruster upgrades upon customer request.

If you often sail alone, a DC Speed Control system in combination with both bow and stern thrusters, along with the unique Hold function, can be incredibly valuable for smooth mooring operations.

It’s important to note that thruster power is primarily determined by the boat’s profile rather than its weight, contrary to common perception. By assessing factors such as the boat’s total wind area, pivot point, and tunnel location, we can accurately calculate the wind force exerted on the boat and its center point. This calculation enables us to determine the necessary force to effectively steer the bow into the wind at various wind speeds.

Example

For a 45-foot boat, there are four standard thrusters to choose from. If your boat has a small profile and is primarily used in favorable conditions with minimal wind, the SE80 thruster would be suitable. If you require more thrust without the need to increase the tunnel diameter, the SE100 thruster is a viable option. However, if your boat can accommodate a larger tunnel diameter, you have the choice to increase the tunnel diameter to either 215mm or 250mm, allowing you to select the thruster that best suits your boat’s needs.

Conclusion

When determining the appropriate thruster size, two main factors come into play: the boater’s requirements for thrust and the boat’s size and hull type. By considering these factors, you can make an informed decision and select the optimal thruster for your specific boating needs.

Important: By increasing tunnel diameter, the thruster is more efficient and generates less noise.

MAX POWER

How to choose the correct Thruster for your Boat

Selecting the appropriate thrust rating, whether for a tunnel thruster or a retractable thruster, is crucial for every boat owner. To simplify the complex calculations involved in considering various boat design variables, we have developed the following charts. These charts are designed to facilitate your decision-making process, making it easier for you to choose the right thrust rating for your specific needs.

Tunnel thruster Selection Chart

Retractable thruster Selection Chart

To utilize these charts effectively, there are two factors, aside from your boat’s length, that you must determine:

The relative size and wind area of your yacht:
When considering a boat of a given length, the area exposed to direct side wind can vary depending on the design. Additionally, the underwater shape and total weight may differ significantly. However, most recreational boats, whether motor or sail, can be classified into one of three categories: cruising, fast cruising, or super-fast cruising.
The conditions in which you use your boat (required thruster force):
Each boat owner has unique usage requirements. For instance, an expedition yacht on a world cruise will have different needs compared to a picnic boat moored on a lake. Consequently, some individuals may desire a more powerful thruster than others. If your boat’s size falls within the range of multiple thrusters on the selection chart, the choice of thruster should be based on the specific situations and conditions in which it will be used.