Add a continuous type spinnaker halyard to almost any beach cat and you can raise the mast alone. Rig the mast either resting on rear beam or have a rear support, even just a step ladder behind the boat. Tie off the head end of the spinnaker halyard to the bridle/forestay attachment point, raise the mast, tighten and cleat the halyard. Now you can walk around the front and pin your forestay.

Oh yeah, you can now fly a spinnaker off that mast raising device also :-)