Sonico's second build

I wanted to try a slightly different board than usual. The battery and electronics hatch represents for me the most delicate point of the whole project. The sealing is the critical point: such a large seal and its large hatch are subject to the weight and to the motion of the rider and this is the main cause of failure.
I developed a different concept: the hatch is not on the deck of the board but on the stern. In this way the hatch and its gasket are small in size and not subject to bending forces.
This concept has the drawback that accessing the connections is inconvenient as the space is very limited but this is not a big problem because inside the locker there are only the battery, the two power wires of the ESC and the receiver.
To avoid the use of the water pump, the cooling is passive, placing the ESC in contact with the mast plate below the board as others have already experienced successfully.


Great design. There might be a commercial brand using the stern connection, half way between PWRFoil and LIFT. Are the Amphenol connectors providing a good galvanic resistance in water ?

That’s a great idea, love it.

If I build another board which I probably will, it would be great to go down this route.

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Thank you SoEFoil.
I didn’t know there were boards with battery access at the stern, can you send me the link to the product? I’m curious to see how they worked out some of the details.
Amphenol connectors are theoretically ip68 (if correctly mounted) but in my situation the battery compartment is perfectly watertight, so they stay dry.

Nice, I had in mind something similar. A box with all the electronic, battery ect on which would connect the mast. Then just slide it in and out of the board. Would allow to change board size/shape easily ect.
You pretty much did it, would just need to tweak it a bit so the mast connect on the box directly

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Here a video of the first tests in the water:


How is the battery discharge

Hi, battery current is about 20/25A foiling and 35/45A in take-off.
The motor current is 50A foiling and 90/100 in take-off.
The power is about 1000W foiling and 2000W taking off

would you mind talking about material choices here? I’m curious.

Lacroix Vortex Efoil – Lacroix Boards
Found it but just 3D and probably not the definitive version…


@SoEFoil thank you!
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You have @virus on youtube who has used the same principle in 2020 with a long battery inserted by the stern too.

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What silicone to use to make a mast gasket. (one side is in the form of cnc, and the other side how did you make it flat. What is the transmitter in the picture?

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