The photo above shows the aft side of our Catalina 27 MastGaters sail track gates. It illustrates how the the sail track is filled so the slides will pass smoothly by the entrance slot when the sail is doused. The reef cringle can slide right to the gooseneck for a cleaner reef. It is also easier to cover your sail at the end of the day.
The shape of the sail track which is extruded into the mast creates a challenge on the Catalina 27. Because the track stands proud of the mast contour, there is not much space for the gate. We build our MastGaters wider than the mast track with additional material at the outboard edge for added strength. Fits a Catalina 27 mast with 5-1/8" nominal entrance slot height.
These new gates:
• Provide a transition across the mast track sail entrance slot
• Allow sail slides to move past the entrance slot for reefing
• Reef right down to the gooseneck from the security of the cockpit
• Prevent slides from falling out of the mast track when the sail is doused
• Includes 12-24 machine screws and proper drill and tap for installation
• Are easily removed to stow the boom at the end of the season
• Set of 2 for Catalina 27 includes drill and tap for easy installation
1) When you reef, you will want to verify the sail slides have dropped below the MastGaters before hauling on the reef line outhaul. If a slide is in the middle of the gate when you winch on the outhaul, you might bend the gate.
2) Sometime late in the Catalina 27's production, Catalina Yachts changed the shape and size of the sail entrance slot which is machined into the mast. The entrance slot in early masts (for which the above MastGater is made) was relieved to both port and starboard of the centerline of the mast. Total entrance slot height was about 5" depending upon how it is measured. See the photo below for a reference. Later masts, built after December of 1983, were relieved only on one side (usually to starboard) and total entrance slot height was only about 3-1/2". If you have a newer Catalina 27, check the single mast gate pictured below.
3) The sail track gate entrance slot was machined into the mast using a milling machine which used hand wheels to adjust the mast position as it was being milled. As a result, the height and width of the gate milled in your mast can vary slightly. Occasionally a new MastGater will need to be modified slightly to achieve a perfect fit to your sail track gate. See "More Images" below for more information. 
