As for leveling the boat, we stick one of the really inexpensive bubble levels right on the mast step.
What's to say the mast step is suppose to be level? Measure vertical from boot stripe to bow pulpit. Repeat and match measurement at transom. Pull a monofilament string tight between those two points and use a string level (small light level that hangs on the string at the middle). If the boat isn't level, measure the difference between level and the boat's orientation. Then, you can lay that out on a piece of graphic paper to scale and draw a perpendicular line from the level line that represents the hanging halyard. Draw it to scale (cord length = mast height) draw another line that represents the perpendicular to the actual orientation. Now, draw a line that represents the desired rake of the mast to that line that starts at the point where mast and halyard meet at the top and intersects the line that represents the actual orientation of the boat. Measure, on your scaled drawing, the distance of desired rake to the perpendicular of the orientation line. Then, measure the distance that leaves between the actual plumb (halyard fall) to the raked mast line.
If your schematic is accurate you will find the distance the halyard needs to hang from the mast as your boat sits on the hard. Easier than correcting an unlevel boat. About 10 min to draw and maybe a couple hours to measure.
Also, it seems obvious, that's why it might get overlooked but, check the lateral step of your mast. With too much tension on port or starboard stay you could also experience a poor helm.
Bow heavy and your center of lateral resistance moved forward, stern heavy and out moves aft.
However, the easiest and I think the best way to set your rake is in the water. Rake doesn't matter until then. You retension all your stays when you put your boat back in the water anyhow.
Good luck and great sailing
- Will (Dragonfly)