---
title: How To Determine Motor Underwater Depth?
description: How To Determine Motor Underwater Depth
---
[Skip to content](https://support.newportvessels.com/knowledge-base/how-to-determine-motor-underwater-depth#main-content)
English
Show submenu for translations
.png?width=600&height=70&name=Newport_Full%20Logo_Navy%20(2).png)
Open main navigation
Close main navigation
- English
Show submenu for translations
- Contact us
Contact us
How can we help you?
- There are no suggestions because the search field is empty.
1. [Newport Knowledge Base and FAQ's Explained](https://support.newportvessels.com/knowledge-base?hsLang=en)
2. [FAQs](https://support.newportvessels.com/knowledge-base/faqs?hsLang=en)
3. [Trolling Motor](https://support.newportvessels.com/knowledge-base/faqs?hsLang=en#trolling-motor)
# How To Determine Motor Underwater Depth?
### Trolling Motor Motor Depth(NV, Kayak, X Series, L Series, Pontoon)
When you receive your trolling motor and are ready to mount it on your vessel’s transom, it’s crucial to ensure that the motor is set at the correct depth for the best performance. Proper motor placement helps avoid issues like cavitation and ensures smooth operation during your time on the water.
For our trolling motor series (NV, Kayak, X Series, L Series, and Pontoon), we recommend placing the motor **10 to 12 inches below the waterline**. This depth strikes a balance between efficiency and preventing damage to the motor.
If the motor is placed too close to the water’s surface, especially when running at higher speeds, cavitation can occur. Cavitation happens when the propeller spins too quickly in a low-pressure environment, causing gas bubbles to form underwater. You’ll know your motor is cavitating if you notice **splashing** or **air bubbles** near the motor.
If your motor starts cavitating, simply **turn off the motor** and adjust its depth to resolve the issue. Here’s how:
1. Locate the **height adjustment collar** on your trolling motor.
2. Move the collar **towards the top** of the motor to lower the motor deeper into the water.
3. Once the motor is at the right depth (10-12 inches below the waterline), the cavitation should stop.
On the other hand, if the motor is placed too deep into the water, the motor will not push the boat properly. The propulsion of the propeller will not feel as strong or reactive. To fix this issue, simply adjust the depth of the motor to be closer to the surface of the water between 10-12 inches of depth.
### NK Series Lower Motor Depth
The NK180Pro motor has an overall shaft length of 21.7 inches and the NK300 has an overall shaft length of 24.60 inches. Once the motor is installed on the kayak motor mount and the height adjustment collar or steering triangle is in place. We recommend adjusting the height so that the lower motor with the propeller is roughly 6 inches below the water. 6 inches below the water without any obstructions in front of the motor that blocks water flow, is the suggested depth for optimal performance.
- [FAQs](https://support.newportvessels.com/knowledge-base/faqs?hsLang=en#main-content)
- [Trolling Motor](https://support.newportvessels.com/knowledge-base/faqs?hsLang=en#trolling-motor)
- [Motors](https://support.newportvessels.com/knowledge-base/faqs?hsLang=en#motors)
- [Support](https://support.newportvessels.com/knowledge-base/support?hsLang=en#main-content)
- [My Account & Orders](https://support.newportvessels.com/knowledge-base/support?hsLang=en#my-account-orders)
[.png?width=600&height=70&name=Newport_Full%20Logo_Navy%20(2).png)](https://support.newportvessels.com/?hsLang=en)
[mailto:email@email.com](mailto:email@email.com)
Copyright © 2025, Newport