In short - no. They all rely on basic o ring set ups that at some stage seem to let water in. Something that may be worth considering is fitting a cable entry similar to what is used on ships - basically an inverted "U" - bit like this
http://klober.co.uk/shop/product/flavent-cable-outlet
either big enough to pass an Anderson connector through into the anchor well corner to start with preferably just in case you ever get water in. It could be made smaller by leaving the ring terminals on the motor and bring it into the cabin onto a pair of posts with wingnuts.
To clarify, my plug is under the coaming out of the spray.
Finished the wiring for the charger and batteries, mounted the MG unit on the bow and have wired up the motor with enough cable to change to a deck plug set up to enable the use of the quick release mount when I find a deck plug and socket that i'm happy with. Looking at the "Battery Tender" trolling motor plug from the US it has some good reviews and looks solid.
BigE
Wiring and batteries , anchor fitted
BigE
Fitted shaft stabiliser today.
BigE