One of the questions we sometimes get, especially regarding refits, is about installing a single BlueNav motor slightly off the boat’s centerline. Does this “de-axed single-motor” setup affect performance or those smart BlueNav features we love?
We chatted with Matthieu, our Head of Software here in Arcachon, to get the inside scoop.
Q: Bonjour Matthieu! Thanks for taking the time. Let’s dive into single-motor installations. If a BlueSpin motor can’t be placed perfectly on the keel line and is slightly offset, how did you program our motors to ensure the propulsion direction is impeccable even with this offset?
Matthieu: This capability is fundamental to the BlueNav control system design. It hinges on two core elements: our motor’s ability to control the direction of its thrust at a 360° angle, and the intelligent software algorithms that govern it. We don’t just push water; we precisely direct the thrust vector. The software is programmed to understand the relationship between the commanded direction (where the user wants to go) and the boat’s actual resulting movement (what the boat must do).
Q: How does the system ‘learn’ about the offset and know how much to compensate?
Matthieu: It’s achieved through a specific calibration process during the system’s initial commissioning by a certified installer. Using integrated sensors – like the compass for heading and the GPS for speed – the system performs maneuvers to precisely measure the effect of the de-axing. It quantifies the optimal corrective thrust angle needed to counteract the offset for any given command. This compensation factor is then stored and applied continuously and automatically whenever the motor is active. Essentially, the system learns the boat’s unique configuration.
Q: That’s impressive! So, if the system is constantly compensating for the offset, do all the advanced BlueNav software features still work correctly in this configuration? Thinking about Heading Hold, our Virtual Anchor…
Matthieu: Absolutely, yes. Because the foundational control layer is already ensuring the boat moves precisely in the commanded direction despite the physical offset, all the higher-level features built upon that layer function perfectly. Whether it’s the Autopilot maintaining a course, or the Virtual Anchor holding position, the underlying software automatically applies the necessary thrust vector compensation. The features command a direction, and the core system delivers it accurately, regardless of the motor’s de-axed position.
Q: Are there any limitations?
Matthieu: The only feature that cannot function in a single-motor setup (whether de-axed or not) is pure lateral docking – moving the boat directly sideways. This isn’t strictly due to the de-axing, but rather the physics of a single thrust point. To push a boat sideways without any forward/backward motion or rotation, you need two distinct points of thrust, ideally spaced apart, to create a ‘couple’ force. Our twin-motor configurations excel at this, but it’s physically impossible with only one thruster.
Q: So, the key takeaway for boat owners and installers is that a de-axed installation for a single BlueNav motor isn’t a barrier to performance or accessing almost all smart features?
Matthieu: Precisely. It offers significant installation flexibility, especially valuable in refit projects where space and existing structures might dictate a slightly offset position. Thanks to our intelligent software and calibration process, owners can be confident they’ll get the pinpoint directional control and the full benefit of features like Heading and Course Hold, Virtual Anchor, and intuitive steering, without needing perfect centerline placement. The system smartly adapts.
Q: Fantastic, Matthieu. Thanks for clarifying that for our readers!
Matthieu: My pleasure! Happy boating!
