watertight deck connection

Shadowcatcher

I need help in finding a watertight from the solar panel into the teardrop trailer connection. What I have is a Perko watertight deck plug sitting on top http://www.perko.com/catalog/category/lighting_fixtures/product/357/
The 180W panel when not attached to the teardrop sits on top of the garage attached to a grid tie inverter, (a watt generated is a watt saved).
I don't know if I am being overly concerned about voltage drop it is a high voltage panel.