K4 Wireless Kayak & SUP E-FIn Motor with Remote Steering.
Perfect match for Saturn MSUP365, FSUP380 Mini Skiff, and all Saturn inflatable kayaks.
The K4 electric fin delivers powerful and efficient performance with a 400W high-efficiency brushless motor reaching speeds of 5mph (9.6 km/h). Cruise efficiently at 5–6 km/h using just 100W, or switch to full power when you need speed.
Aviation-grade metal steering servos provide smooth, precise left and right control, making maneuvering easy even in waves. Wireless Bluetooth remote control eliminates cables and delivers instant, millisecond-level response for speed, steering, and one-touch cruise control.
Compact and lightweight at only 1180 g, the K4 installs in seconds using a standard 9-inch quick-release fin with no tools required. It fits kayaks, SUPs, inflatables, canoes, and other small watercraft. With a simple DIY it can also be mounted on a transom of small boat.
The B4 423 Wh waterproof battery delivers up to 5 hours in slow speed mode or 1.5 hours at full speed. Beginner-friendly operation, real-time display data, and universal compatibility make the K4 electric fin an easy upgrade for effortless water adventures.
Smart Control and Agile Maneuvering
Aviation-grade metal steering servos provide precise left and right control, allowing smooth turns and confident handling in waves. Glide effortlessly across the water with responsive, intuitive steering that feels natural from the first ride.
Wireless Bluetooth Remote Control
Advanced Bluetooth technology removes cable restrictions entirely, giving you true freedom on the water. The compact handheld remote pairs instantly with one-touch connection and delivers millisecond-level response for smooth speed changes and agile steering. Control feels immediate, accurate, and effortless.
Compact, Lightweight, and Easy to Transport
Designed for portability, the K4 is compact and lightweight while delivering serious performance. The standard 9-inch quick-release fin allows tool-free installation and removal in seconds. Compatible with inflatable boats, kayaks, canoes, SUPs, and small watercraft of all types.
- Total Weight: 1180 g
- Motor Only: 1000 g (excluding cables)
Beginner-Friendly, Easy to Use
The wireless remote makes speed and steering adjustments simple and intuitive. One-touch cruise control allows hands-free operation, making the K4 easy to master even for first-time users.
B4 Battery Specifications
- Battery Capacity: 423 Wh
- Battery Weight: 2570 g
- Charging Interface: USB-C PD 3.1, up to 100W
- Waterproof Quick-Connect DC Port: 24V
Runtime with K4 Motor
- Low Speed Mode: up to 5 hours
- Full Speed Mode: up to 1.5 hours (depending on vessel hull configuration, weight load and water condition)
Why Choose the K4
Experience powerful underwater propulsion reaching speeds of 5 mph. Enjoy precise, responsive control with a Bluetooth remote that displays real-time speed, battery level, RPM, and distance traveled. One-touch cruise control enables relaxed, hands-free cruising, while aviation-grade steering servos provide smooth, confident maneuvering. The universal quick-release fin system fits virtually all kayaks, SUPs, canoes, and inflatables, making installation fast and hassle-free. Lightweight construction ensures easy transport without sacrificing performance.
Simple Setup in Minutes
Install the propeller and protective guard, securing them with the included screws. Connect the battery and allow the system to complete its power-on self-test. Turn on the remote for automatic pairing. If pairing does not start, hold the right button for four seconds to enter pairing mode.
Included:
- K4 electric fin
- B4 Li battery
- Remote
- Battery charger
- US-Box fin adapter
- IMPORTANT: Rinse the K4 with fresh water after use in saltwater. See more warning and tips at bottom of this page.
- IMPORTANT: K4 efin is best suited for seating, not standing.
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Warnings and Quick Tips
- Expect a short learning curve to get familiar with the electric fin’s steering. As with any vehicle or watercraft, always slow down before turning. The steering is very responsive. Do not make sudden turns at full speed, as this may cause a narrow vessel to tip or result in falling into the water.
- Do not push the steering lever aggressively. A very light push left or right is enough to change direction. The trim buttons located to the right of the main steering lever can also be used for small directional adjustments.
- Do not attempt to steer a SUP while standing unless you have excellent balance and agility. The K4 electric fin is best operated while sitting on a SUP, kayak, or mini skiff. A lower center of gravity provides much better stability. Extra-wide mini skiffs or kayaks are recommended for heavier riders. Always get a feel for the turning force at low speed before increasing speed.
- The remote includes a wrist strap. For hands-free use, an optional neck lanyard can be attached to secure the remote and keep your hands free.
- To extend the life of the K4 electric fin, always rinse it with fresh water after use in saltwater or muddy conditions.
- The K4 comes with a prop guard. If operating in water without swimmers or heavy vegetation, the prop guard may be removed to slightly increase speed.
- If using the electric fin in areas with seaweed, briefly engage reverse to help clear vegetation from the prop guard.
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