HO Scale Lifeboats (and some larger vessels, too)

[Sumpter250]

Bear:
There are many ways the davits, and falls ( the lines that actually lift/lower the boat ) can be rigged.
With wire falls, they are usually wound on a winch drum, and when the boat is in the stored position, the winch brake is set.
With fiber lines, the falls are belayed to a cleat near the base of the davit ( When the boat is full up, a "stopper" is tied to the in-haul line, to hold it so that the line can be taken off the winch drum, cleated , and then the loose end coiled and lashed to the same cleat. There is usually a single sheave block, deck mounted just beneath that cleat, that guides the fall towards the winch drum. The stopper remains in place until the falls are once again secure on the winch drums, for lowering.) The best suggestion I can give, would be to find pictures, or better, a vessel similar to your ferry, and see how the boat falls actually run, and how they are secured when the boat is on the davits.
Looking forward to seeing how this goes.