SiFly eFoil — frequently asked questions

A continuous beep almost always means the hydrofoil's electronics have no connection to the board's main computer. On Adventure boards, first check the communication connectors in the battery compartment. If a restart doesn't help, do a hard reset with the magnetic key. If it persists, contact support.

1. Adventure series: open the battery compartment, check that the communication cable to the hydrofoil is securely seated
2. Restart the system (briefly disconnect the battery or open/close the lid)
3. Hard reset: connect the battery to the hydrofoil, place the magnet on the marked circle (power on), then hold a second magnet centered on the main computer module for 30 seconds (Adventure: front of the board/rectangular pad; Stellar/Rider: on the mast, center of the black box), then remove both magnets
4. If the error persists → contact support

Your eFoil is stuck in Limited Power Mode, a deliberate protective throttle. Three causes are possible: an overheated battery, a charge level below 8%, or a missing session in Business mode. Let the battery cool down, recharge it, or set up a session in the SiFly app — then the motor will run at full power again.

1. Battery overheated → let it cool down
2. Charge level below 8% → charge it (at 8% the board deliberately throttles as a return-to-shore reserve, only released above 8%)
3. Business mode → set up a session in the SiFly app

This means the trigger is no longer calibrated correctly — the zero and full-throttle positions are off. You fix this with the calibration routine in the remote's menu. Go through it carefully until "Done" appears. Stay clear of the spinning propeller and the water while doing this.

1. Open the menu (safe mode): hold "+" for 3 sec, then hold "F" for 3 sec, select "Calibrate"
2. Sequence, each step starts with "F" and ends with a vibration: Start (F) → release trigger+F → release+F → pull/hold+F → release+F → pull/hold+F
3. "Done" = finished; if "Calibration ERROR" appears, hold/release the trigger consistently at each step until the vibration and try again

This happens when the board, battery, and remote aren't running the same firmware. Check the versions of all devices under "Specifications" in the SiFly app and bring them to the same version. From version 2.2-365 onward, you only need to update the board — the battery and remote update automatically.

1. In the app, compare the firmware of the board/hydrofoil, battery, and remote under "Specifications"
2. Connect the board to a stable WiFi network and install Firmware A + B (both!)
3. From 2.2-365 onward: only update the board, battery + RC follow automatically (~5 min); for older versions (≤2.0-350) update manually via each device's page
4. Verify success: the "Firmware" and "Sensorhub" fields show the same version; never ride with mismatched versions

Usually the battery is too hot or in a protective state. To charge, its temperature must be below 40°C — connect via the SiFly app and check the temperature and any error message. If the voltage is too low (a low-voltage error), the charger won't start; in that case use the app's recovery charging mode.

1. Connect to the battery via the SiFly app, read out the temperature and error code
2. Above 40°C → let it cool down in a shady, cool spot
3. Check the contacts on the battery and charger for cleanliness/dryness, remove salt/moisture with a soft cloth
4. Low-voltage error → recovery charging mode: connect the charger via the app, select recovery, keep your phone nearby with the app open; after a few minutes continue charging normally
5. If it persists → contact support

A red blinking battery LED with no startup tone signals an error detected by the battery management system — connect via the SiFly app and read out the error code. If the LED blinks even without the magnetic key attached, the battery firmware needs a reset using a second magnet. If the error persists, contact support.

1. Red LED + no startup tone → connect via the app, read the error code + explanation, follow the instructions; otherwise contact support
2. LED blinks without the magnetic key → hard reset with a second magnet: second circle on the underside of the battery, hold both magnets on their circles for 30 sec
3. If the error persists → contact support (never open the battery yourself)

The drive's rotation direction is set incorrectly. Correct it in the SiFly app under "Rotation Direction": propeller hydrofoils spin clockwise, newer drives like the SiFly Jet spin counterclockwise. Always check this setting after swapping the propeller or drive unit.

1. SiFly app → device settings → "Rotation Direction"
2. Propeller: clockwise; SiFly Jet / newer systems: counterclockwise
3. After every propeller/drive swap, check and adjust the rotation direction

Rinse the board and foil thoroughly with fresh water after every ride, paying special attention to the motor and rubber seals — crystallized salt on the propeller shaft damages both. Afterwards, check all connectors for corrosion and the battery for cracks and an intact pressure valve. Blow out any moisture.

1. Rinse board and foil thoroughly with fresh water; pay attention to motor + rubber seals, remove salt from the propeller shaft
2. Inspect all components for damage before and after every session (seals/EVA pad/propeller are wear parts)
3. Are the connectors clean and free of corrosion? Blow out moisture or wipe dry; only connect wet contacts once dry
4. Check the battery: no cracks, pressure valve clear (not blocked, damaged, or corroded)

Never keep using a damaged battery. A cracked battery that comes into contact with water can suffer internal damage and, in the worst case, corrode or explode. Immediately place it outdoors, monitor it from a safe distance until it's completely dry, and contact SiFly support right away.

1. Immediately take a damaged/cracked battery out of service — don't ride, don't charge
2. If it's been in contact with water: place it in an open area right away, monitor from a safe distance until completely dry
3. Never open, puncture, or burn it; don't tamper with the pressure valve
4. Contact SiFly support or dispose of it properly (free return to SiFly for recycling)

If you leave the eFoil assembled for a longer period, disassemble it every three to four weeks and apply TefGel to the screws and threaded inserts — this prevents oxidation. Treat the communication and power connectors with dielectric grease every few weeks to guard against electrolysis, and grease the O-ring at the top of the mast plate.

1. Disassemble every 3–4 weeks and apply TefGel to screws + threaded inserts (oxidation protection)
2. Protect communication and power connectors every few weeks with dielectric grease (against electrolysis)
3. Grease the O-ring at the top of the mast plate with the same grease (seal)
4. Never store in direct sunlight / above 50 °C for extended periods; not wet in the board bag, not in a hot car

To turn it on, hold "-" and "F" for four seconds. The remote starts locked (lock icon). To arm it, press "X", then "F" within one second — you now have five seconds to hit the throttle. Use "-" and "+" to choose among 20 gears; set the mode (Easy/Dynamic) in the menu.

1. Turn on: hold "-" + "F" for 4 sec. Turn off: hold "-" + "F" for 3 sec + confirm with "F" (or hold for 7 sec)
2. Starts disarmed (lock icon) — protection against accidental start-up
3. Arming: press "X", then "F" within 1 sec; 5-sec window to give throttle, otherwise it disarms again (RC must be connected to the board)
4. Pull the trigger; change gears with "-"/"+" (20 levels), don't shift up too fast
5. Mode in the menu: Easy (trigger = on/off, good for learning) or Dynamic (fine throttle control)

Pairing is done via the SiFly app, and the remote can only ever be connected to one board at a time. First add the board in the app. Then open the menu on the remote, select "Pair", search for the device in the app, tap "Pair Remote", and select the remote that's found.

1. First add the board in the app: Devices → "+Add" → "Scan" → select board
2. Open the menu on the remote (while disarmed): hold "+" for 3 sec, then hold "F" for 3 sec; select "Pair" (navigate with "-"/"+", "X" to go back, "F" to confirm)
3. In the app, select the board/hydrofoil → tap "Pair Remote" → tap the remote that's found → "Success" (Bluetooth + location must be on on your phone)

Only charge the battery under supervision using the supplied SiFly charger, in a dry, cool, shaded, and well-ventilated spot. The connectors must be clean and dry. Attach the magnetic key — the LED shows the charge level in green and blinks blue while charging. Solid green means full; let it cool down afterwards.

1. Place battery + charger on a dry, flat surface; dry connectors with a soft cloth/compressed air, check that the ports are clean/dry inside
2. Plug in the black power cable until it clicks; the red (positive) connector is keyed — insert it sideways with the top facing out, until it clicks
3. Attaching the magnetic key activates the battery; green blinking = charge level (1× = 0–20%, … 5× = 81–96%, solid green = 96–100%), blue between measurements
4. Once done (solid green + fan stopped): remove the magnet, unplug the charger from the mains, then disconnect the connector at the base (not by the cable)
5. Only use the supplied charger; never charge with damaged connectors; let the charger/connectors cool down before touching

Store the PowerCell LR cool, dry, well-ventilated, and frost-free at 30 to 70% charge, and check the level at least monthly — never leave it below 10% for more than a week, and never below 0 °C or above 60 °C. For transport, a maximum of 30% charge applies; never fully charged when flying.

1. During breaks longer than 3 weeks, keep the charge between 30% and 70%
2. Store cool, dry, ventilated, frost-free; never above 60 °C (no hot car, no direct sunlight), never below 0 °C
3. Never below 10% for more than 1 week; check the charge level at least monthly and recharge into the healthy range
4. Transport: maximum 30% charge, never fully charged by plane/over long distances; UN 3480 hazardous goods → shipping only via specialists with an MSDS