| Having used this particular gin pole on my Marsh Hen, I can say that it does work satisfactorily, but some caution is in order. Because of extreme pressure generated at the tabernacle, the gin pole and metal prongs must be made of very sturdy materials. The holes that slip around the tabernacle bolt should fit snugly, and it's best to use thru-bolts when securing those metal prongs to the gin pole. I tried screws and they eventually failed.
If made solidly, and used cautiously, this pole does take much of the strain out of mast raising, but care must be taken in both it's construction and operation. Be sure to crank slowly!
For those able, walking the mast into position remains the simplest and by far the quickest technique. The time taken to rig a gin pole, and the slowness of the trailer winch, turns mast raising into a ten to fifteen minute operation.