coating is nice, but causes problems if you need to return the esc for repair. I see far to many people strapping their escs to a inside hull surface. Most times if water does get into a hull, its limited to some sloshing water. not a complete breach. mount the esc on a box or lifted surface. that will go a long way towards keeping water out. also coat the esc with a petroleum based water resistant item like Corrosion X, AeroPlate or similar.