I keep my boat upriver from Ft. Washington and I''m having trouble understanding what all the fuss is about. Presumably if Ft. Washington is a full service marina, mast stepping/unstepping would be a basic service offered along with launch/haulout services.
I think you ought to be able to find some facilities somewhere, if not at Ft. Washington, to step your mast. If need be, motor the boat with mast unstepped to a marina nearby that has a crane tall enough to do the job. But it''s hard to imagine that Ft. Washington does not have a crane that can reach about 30 feet; that''s all you need.
You also ought to be able to rig a temporary a-frame (similar to a gin-pole; it improves the angle of effort lifting the mast from the head, and also gives side-to-side stability if the a-frame is securely mounted to the deck) pivotally clamped to the deck to allow you and some helpers to safely step the mast manually.
Another neat trick I''ve heard described here at Washington Sailing marina is to use the launching cranes by the docks. The boat is tied securely to floating docks, lined up so that the centerline of the boat is aligned with the top of the crane and the crane hook. A line from the masthead (jib halyard, etc.)is threaded through the lowered end of the crane hook, the hook is then raised and gives good purchase on lifting the mast (similar to a gin pole idea commonly used), and you can pull the mast up with pretty good stability (at Washington marina you could even attach this line to a vehicle, since the cranes have pavement behind them). I''d recommend you motoring upriver to our marina to try this, but the launch cranes are not really tall, say 16 feet or so above water level at low tide, and might not be tall enough for stepping your 55 footer.
email me if you want more ideas for crane/assisted or other methods of mast stepping (firstname.lastname@example.org)