Mast Rake for Cape Dory 30
If you have lee helm the mast may be too far FORWARD. I sailed on an Island Packet cutter that often had lee helm and it too had fairly old sails.
1) is the main going all the way up the sail track?
2) Is the main sail from another boat (recut)?
3) have you measured the rig dimensions, i.e. the I,P,E measurements? I=mast height to the deck (not cabin top); P=boom to top of mast OR mainsail luff**; E=mainsail foot length. Are they equal to the specs for the CD30 as advertised?
If the mainsail luff is too long** the boom would set too low. Also if the mainsail foot or leech were too long it would droop.
4) call a local sailmaker to see if they will sail the boat with you to establish a) what is wrong b)if anything can be done with the current sails c) recommend new sails necessary to put the boat right. They will mostly do this for free but may be somewhat aggressive about selling you new sails.