Scout wrote:

Question: if a square rig's sails could be turned 90 deg (with the wind
abeam), and a centerboard or sideboard were dropped to resist sideways
movement, and enough ballast were present to prevent capsize, could the boat
move in a track that is more perpendicular relative to the wind?


More perpedicular? More perpendicular than what? Since a square rigger
can sail on a beam reach 90 deg to the wind without much problem, the
answer would be no. You can't get any more perpendicular than 90 deg.

Somehow I don't think this is what you are asking...

I.e., is it
only the "lift" that makes a boat move forward when not going downwind?

No, there are other forces like current and waves that make the boat go
in certain directions.

Somehow I don't think this is what you are asking either...

//Walt