Comments about Marinco Marinco Reverse Y Adapter 50A 125/250V to 2-30A 125V:

This is the best way (and the only safe one) to get some power from twin 125v/30a dock service to 125/250v 50a boat electrical inlet/s. My boat has twin 125v/50a inlets so I use the 167RYN2 (now renamed to the RY504-2-30) to connect from the twin 125v/30a dock outlets to a 12' 50a 125/250v (6152SPP-12SC) power cable and then to a 125/250v 50a Y-adapter that splits the 250v back to twin 125v cables that attach to the boats inlets. You'll only get 30 amps on each circuit but it's enough to run on-board appliances that total less than 30 amps. (Just a note: dockside connections must be wired correctly - including polarity). This product has excellent construction and it works!