I am sure some have seen: http://www.cabratec.com.
No prop guard and shipping with LIPOs.
Here is their explanation why they think it’s safe:
Why don’t you have ducted propeller?
Many projects use some Kort nozzle (non-rotating ring) around the propeller claiming it as a safety and efficiency feature. The true is, when falling from hydrofoil board, you will never fall on its bottom! The same way when falling on bike you will never fall on your wheels .When using hydrofoil with kite, this rarely happens, but it is always kite that is towing you over the foil after you felt.
In accord with manual you are supposed to switch ON the board by remote control not until you get to deep water. Having it ON is well signalized. Disobeying this common sense rule, you may obviously harm yourself or others when manipulating with the board. At this point open propeller is more likely to cause injury, but less serious than most ducted propellers. Getting anything between the duct and propeller is fatal. To be ducted propeller called more safe, needs to be prety long,100% preventing anything to reach the propeller. We have not seen any like that so far.
Efficiency increase works at this propeller size to 4-5 km/h, anything over that just increases drag.
I can tell everyone from my own foiling experience with SUP foils, efoils and kite foils that this is total BS. Yes you can fall on the foil. And you can fall into that open prop.
My concern is that if companies don’t take safety serious we will be shut down quickly.
What is everyone thinking?