Cruising in Maine recently. Decided to indulge myself and took a slip for a few nights in a very expensive marina. Attempted to connect shore power cord to nearby pedestal and discovered that the pedestal outlet rain cover prevented my standard Marinco 30 Amp cord from engaging. Explained problem to the dock hand who said, "Oh yeah those don't fit here, let me get you a 50 Amp adaptor." He handed me a 50A splitter cord adaptor with two 30A ends. I examined that and found that the terminals were all pitted and burned. Connected it anyway and for the first time in all my years of sailing my reverse polarity light came on. Removed the marina's adaptor and fetched my own. Connected that and still reverse polarity indicated. Marina staff had gone home for the night so did without shore power for that night. Next day explained problem to new dock staff. Guy said, "Oh that pedestal. Thought they fixed that. Plug into other side, that should work." That side did work. This marina, BTW, charges $30 extra for each night for a 30A electric hook-up. The moral of this story is be cautious with marina electric wiring. My only consolation, at least I now know that my reverse polarity indicator actually works.