I am looking to purchase a small sailboat, and want to know if my girlfriend and I could lift the bare hull minus rigging to cartop it. Specs variously list the displacement or the "hull weight". I'm not sure if the "hull weight" includes the rigging, mast, sail(s), etc. All that stuff will probably weigh 20-30lbs, and lifting a 90lb hull vs lifting a 120lb hull will make a world of difference.
As Rory states in his answer, hull weight is just the hull. But you need not worry, the mast, rudder, center board, sail, etc. Are usually loaded separately from the hull of the boat.
For small two person sail boats, around 100 pound. All the parts except for a couple pieces of hardware come off.
- The mast slides in and out of a mounting well.
- The sail and spars either come loose, or fold up with the mast
- The center board (keel) slides in and out through a hole in the top (centreboard trunk)
- The rudder clips on and off (it should also fold up, but not all do)
- The rigging is some rope (line) that generally winds around the sail and spars for travel/storage.
If they don't come off, keep looking. The added weight would be the least of your issues. Generally the bare boat is carried to shore, the mast and sail are mounted at the waters edge, the rudder is mounted and folded up. Once you have pushed off from shore the center board and rudder are lowered. Anything else would be a huge headache to try and maneuver.
You may also want to consider a community sailing class. Local clubs often offer them for a vary reasonable price.