🌊 Powerful. Silent. Built for the Water.

The Firduo TUNA Underwater Thruster is a high-performance electric propulsion unit engineered for DIY eFoil, electric surfboard, SUP, kayak, and hydrofoil builds. With up to 18.5 KGF of thrust at 1430W and a hydrodynamic fluid design that minimizes drag, the TUNA delivers raw power with exceptional efficiency — so you spend more time riding and less time charging.

Available in CW (clockwise) and CCW (counter-clockwise) variants to match your build orientation. The all-aluminum anodized shell and fully waterproof motor make it ready for serious water use right out of the box.

⚡ Key Features

• ✅ Up to 18.5 KGF Thrust @ 30A / 1430W — enough power for eFoil and surfboard applications
• ✅ Fluid Aerodynamic Design — 360° large-flow water inlet reduces drag and improves efficiency
• ✅ Fully Waterproof Motor — sealed for continuous underwater operation
• ✅ High-Strength Anodized Aluminum Shell — corrosion-resistant, built for saltwater environments
• ✅ Wide Voltage Range — 10S–14S (36–58.8V), compatible with most LiPo/Li-ion packs
• ✅ CW & CCW Variants — Single drive, with the option to freely choose between CW and CCW.If dual drive is required, please select both CW and CCW.
• ✅ High-Thrust Propeller Included — optimized blade geometry for maximum water bite
• ✅ 12AWG Silicone Cable — 900mm length with 4.0mm gold bullet connectors, flexible and heat-resistant
• ✅ Easy Installation — Suitable for paddleboards, surfboards, and kayaks, etc.

📋 Full Specifications

Thrust Performance (13S Reference Voltage)

📦 What's in the Box

• 1× TUNA Underwater Thruster (CW or CCW — per variant selected)
• 3*4.0mm gold male and female connectors
  

🔗 Compatible Builds & Recommended Pairings

• eFoil / Hydrofoil boards — Installed directly on the mast
• Electric surfboards (eSurf / Jetboard) — rear or bottom mount
• SUP / Kayak conversions — Choose the version with tail fin support-Firduo TUNA Underwater Thruster, compatible with standard fin boxes.
• Recommended VESC: Firduo Manatee 100 Pro VESC (supports PPM/UART, waterproof to 5m)
• Recommended ESC: Firduo Walrus 14S Waterproof Brushless ESC—Designed specifically for low-power underwater thrusters -With a 6–14S,waterproof to 5m
• Recommended Remote: VX3 Waterproof Remote Controller (IP67, 1.6" display)
• Complete Kit Option: Firduo 2KW Efoil Kit (ESC + Thruster + Remote bundle)
• Battery: 10S–14S LiPo or Li-ion pack, minimum 30A continuous discharge recommended

🛠️ Setup Guide

1. Select CW or CCW variant — when viewed from behind the board (water-facing side), CW rotates clockwise and CCW rotates counter-clockwise. Single drive, with the option to freely choose between CW and CCW.If dual drive is required, please select both CW and CCW.
2. Mount the thruster — insert into your board's fin box or custom mount. Secure with the provided hardware. Ensure the motor cable is routed away from moving parts and the propeller has clear water flow.
3. Connect to ESC — plug the 3× 4.0mm gold bullet connectors into your ESC phase outputs (A-B-C). Rotation direction can be reversed in software (e.g. VESC Tool) if needed — no rewiring required.
4. Connect ESC to battery — use a waterproof connector rated for continuous current >50A. Verify battery voltage is within 36–58.8V before powering on.
5. Pair your remote — power on ESC first, then remote. Follow your remote's pairing procedure.
6. Water test — start at low throttle (10A / 500W) in calm water. Check all connections are dry and secure before each session. Gradually increase power as you confirm stable operation.

📄 Download TUNA Thruster 2D Drawings (PDF)

❓ FAQ

Q1: CW or CCW — which variant do I need?
This depends on your thruster's mounting orientation. When looking at the thruster from behind (water-facing side), CW rotates clockwise and CCW rotates counter-clockwise. when viewed from behind the board (water-facing side), CW rotates clockwise and CCW rotates counter-clockwise. Single drive, with the option to freely choose between CW and CCW.If dual drive is required, please select both CW and CCW.If you're unsure, contact us with your board specs and we'll advise the correct rotation.

Q2: What ESC do I need to run this thruster?
The TUNA thruster is compatible with any BLDC ESC that supports 10S–14S voltage and at least 30A continuous current. We recommend the Firduo Manatee 100 Pro VESC for best compatibility — it's waterproof, VESC-based, and pre-matched to this thruster's power range. PPM and UART control are both supported.

Q3: What battery do I need, and is it included?
The thruster supports 10S–14S (36–58.8V) battery packs. For eFoil and jetboard use, a 12S–14S LiPo or Li-ion pack with minimum 30A continuous discharge (50A burst recommended) is ideal. Battery is not included. We recommend the waterproof battery (FD13S5P,20AH) for Firduo underwater scooters. Please contact us if needed.

Q4: Is the motor truly waterproof? Can I run it in saltwater?
Yes. The TUNA motor is fully sealed for continuous underwater operation. The anodized aluminum alloy shell is corrosion-resistant and suitable for both freshwater and saltwater environments. Rinse with fresh water after saltwater use to extend service life. Note: the motor cable exit point should be kept above the waterline or sealed with waterproof connectors.

Q5: Can I use this thruster for an ROV, AUV, or non-surfboard application?
Yes. The TUNA thruster's waterproof motor and standard 4.0mm bullet connector output make it suitable for ROV, AUV, USV, and other underwater propulsion applications. The UART/CAN interface on compatible ESCs (e.g. Manatee 100 Pro) supports autonomous or remotely operated vehicle integration. Contact us for application-specific wiring diagrams and configuration support.