Hi Lavi, thanks
The turbines are fully ducted and will allow water to flow through the duct system without entering the fuselage as the various sections are sealed with o-rings. The above pictures are just a hook up and test of the electronics before I make things neat. On other similar sized models I've built I haven't experienced any EMI problems, I try where possible to group the wire runs to minimise this and separate power cables to servo runs, telemetry etc... Unlike other models this will have hours of testing on the water before committing to flight so does give us plenty of time to rectify any issues that arise... I'm sure there will be some.
Cheers, Alex