Boom Height on CD Typhoon?

[PortTack]

I was out on a friend's CD Typhoon the other day and am very interested in getting my own, loved how she handled, but did have one question about the boat. The boom was much lower than I was anticipating when under sail, and you really had to duck under it when tacking/jibing. I'm not particularly tall, 5'11'', so it seemed excessive, to the point that an accidental jibe in decent winds could potentially take someone out. We definitely hoisted the main up all the way up, so I think the problem was elsewhere

Was this issue with how the boat was currently setup? He mentioned that he had just reconfigured the boom setting higher up on the mast, and it looked about as high as it could go before popping out of the track, but it was absolutely lower than something you see here ( https://youtu.be/HryHBibKBzU?t=5m40s ) on sail #767. Any thoughts?

[Gary H]

Boom height is a function of how long your main sail is. A slightly shorter sail provides more headroom but sacrifices a bit of power.

[wikakaru]

We had a similar problem on our Typhoon that occurred because the previous owner had replaced the original main halyard with something ridiculously large like 7/16" or 1/2" and the eye splice at the shackle would jam in the masthead sheave about a foot from the shackle, preventing full hoist of the mainsail. We replaced the too-big main halyard with a 5/16" diameter halyard and now get full hoist. So the problem could either be, as Gary H pointed out, that the mainsail is too long, or it could be that the halyard is too large and doesn't allow full hoist.

[mgphl52]

It's also possible that a non-Typhoon main was put on the boat...