I am assuming you mean the slot for inserting the sail slugs into the sail track. On my 30 there is no "cover". You can buy, from most boat shops, a sail slug which has a thru-bolt, washer and wing nut that is secured above the slot after the sail is inserted. Alternatively you could make your own with a spare sail slug. You may also drill a hole in the track and just above the slot into which you can insert a pin. Any of the above will keep the slugs from falling out.LO