1. Introduction
Thank you for choosing the ApisQueen U2 Mini Underwater Thruster. This manual provides essential information for the safe and efficient operation, setup, and maintenance of your thruster. Please read this manual thoroughly before use and retain it for future reference.
1.1 Safety Warnings
- Water and Electricity: Always exercise extreme caution when working with electrical components near water. Ensure all connections are secure and waterproofed where necessary.
- Propeller Hazard: The propeller can cause serious injury. Keep fingers, hair, loose clothing, and other objects clear of the propeller at all times, especially during operation.
- Voltage Range: Operate the thruster only within the specified voltage range (12-16V). Exceeding this range can damage the motor and void the warranty.
- Overheating: Avoid prolonged operation out of water, as this can lead to overheating and damage.
- Children: This product is not a toy. Keep out of reach of children. Adult supervision is required during operation.
2. Components
The ApisQueen U2 Mini Underwater Thruster package typically includes the following components:
- U2 Mini Underwater Thruster Unit (with integrated brushless motor and propeller)
- Mounting Bracket (if included with your specific package)
- Connection Cables (power and signal)

Figure 2.1: Overview of the ApisQueen U2 Mini Underwater Thruster. This image shows the compact design of the thruster unit, highlighting the propeller and motor housing.

Figure 2.2: Illustration of typical components included with the U2 Mini Thruster. This image depicts the main thruster unit, mounting bracket, and power/signal cables.
3. Setup
3.1 Mounting the Thruster
- Identify a suitable mounting location on your kayak, ROV, RC boat, or underwater vehicle. Ensure the location allows for proper water flow to and from the propeller and does not interfere with other components.
- If using a mounting bracket, securely attach the bracket to your vessel using appropriate fasteners (not included). Ensure the bracket is firmly fixed and can withstand the thrust forces.
- Attach the U2 Mini Thruster unit to the mounting bracket. Verify that the thruster is oriented correctly for the desired direction of thrust.
- Confirm that the thruster is securely mounted and will not vibrate excessively or detach during operation.
3.2 Electrical Connection
The U2 Mini Thruster requires a 12-16V DC power supply and an Electronic Speed Controller (ESC) for operation. The thruster is a brushless motor and requires a compatible brushless ESC.
- Connect the three motor wires from the U2 Mini Thruster to the corresponding three output wires of your brushless ESC. The order of connection may affect the direction of rotation. If the thruster spins in the wrong direction, swap any two of the motor wires.
- Connect the power input wires of the ESC to your 12-16V DC power source (e.g., battery). Ensure correct polarity: red to positive (+), black to negative (-). Incorrect polarity can damage the ESC and thruster.
- Connect the signal wire from the ESC to your control system (e.g., RC receiver, flight controller, microcontroller). Refer to your ESC and control system manuals for specific signal connection details.
- Insulate all electrical connections with waterproof heat shrink tubing or marine-grade electrical tape to prevent short circuits and water ingress.
4. Operating Instructions
4.1 Pre-Operation Checks
- Verify all electrical connections are secure and properly insulated.
- Ensure the thruster is securely mounted and free from any obstructions around the propeller.
- Check the battery level of your power source.
- Confirm that the control system is functioning correctly.
4.2 Powering On and Control
- Place the vessel with the thruster into the water. Never operate the thruster out of water for extended periods.
- Power on your control system and then connect the main power to the ESC/thruster.
- Slowly increase the throttle input from your control system. The propeller should begin to spin, generating thrust.
- Observe the thruster's operation. If any unusual noises or vibrations occur, immediately reduce power and investigate.
- Adjust throttle as needed for desired propulsion.
4.3 Powering Off
- Reduce throttle to zero.
- Disconnect the main power from the ESC/thruster.
- Power off your control system.
5. Maintenance
Regular maintenance ensures the longevity and optimal performance of your U2 Mini Thruster.
5.1 After Each Use
- Rinse: If used in saltwater, thoroughly rinse the entire thruster unit with fresh water to remove salt residue.
- Inspection: Visually inspect the propeller for any damage, nicks, or debris (e.g., fishing line, weeds) wrapped around the shaft. Carefully remove any debris.
- Cable Check: Inspect all cables and connections for signs of wear, corrosion, or damage.
5.2 Storage
- Store the thruster in a clean, dry place away from direct sunlight and extreme temperatures.
- Ensure the thruster is completely dry before storage to prevent corrosion.
6. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Thruster does not spin | No power to ESC; Incorrect wiring; Faulty ESC; Damaged motor | Check battery connection and charge; Verify all wiring connections and polarity; Test ESC with another motor (if possible); Contact support if motor is suspected faulty. |
| Reduced thrust or unusual noise | Debris in propeller; Damaged propeller; Low battery voltage; Motor overheating | Inspect and clear propeller; Replace damaged propeller; Charge or replace battery; Allow motor to cool, check for obstructions. |
| Thruster spins in wrong direction | Incorrect motor wire connection | Swap any two of the three motor wires connected to the ESC. |
| Motor gets excessively hot | Overload; Insufficient cooling (operating out of water); Incorrect voltage | Reduce load; Ensure operation is in water; Verify input voltage is within 12-16V range. |
7. Specifications
| Feature | Detail |
|---|---|
| Model | U2 Mini Underwater Thruster |
| Operating Voltage | 12-16V DC |
| Maximum Thrust | 1.3 Kg (approximate) |
| Maximum Power | 130W (approximate) |
| Motor Type | Brushless Motor |
| Propeller Type | 3-blade (typical) |
| Operating Environment | Freshwater and Saltwater |
8. Warranty & Support
8.1 Warranty Information
ApisQueen products are manufactured to high-quality standards. This product is covered by a limited warranty against manufacturing defects. The warranty period and terms may vary by region and retailer. Please retain your proof of purchase for warranty claims. Damage resulting from improper installation, misuse, neglect, unauthorized modifications, or operation outside specified parameters is not covered by the warranty.
8.2 Customer Support
For technical assistance, troubleshooting not covered in this manual, or warranty inquiries, please contact ApisQueen customer support through the retailer where the product was purchased or visit the official ApisQueen website for contact information.