Excellent reply, thanks. The boomed lateen is obviously the right rig for some uses and has its very good points I had never thought about as I haven't sailed one since 1967 on Kure Island.
It's NINA, not PINTA I was skipper of. We tried everything to go to windward and found that we could make good slightly above a reach, so 150-160 degrees between tacks. This was somewhat a function of the ship always being light and never loaded down. With 50-60 tons aboard she would have done somewhat better. Rigging bowlines would have helped too, but the replica does not have them as her rig is somewhat simplified for ease of handling in her actual use, which is a dockside attraction vessel.
Hard to tell if anyone is right about lateen as it was little documented, but the theory of changing ends on the yard seems far-fetched, as a timber yard is quite a bit heavier on the lower end due to snotter (tack) tackle loading, and your theory gives no advantage in handling that I can see, requires a symmetrical sail and yard and does not seem practical.
Went and looked up the lateen use among the ancients and Lionel Casson (The Ancient Mariners, Princeton, 2nd edition 1991) says that the true lateen and the settee lateen with a short luff were both used, but you're right that the grain ships were square rigged forward, though no definitive proof has been found, and they may have set lateen mizzens.
The large 13th century lateen with a forward raking mast made me start wondering about your ideas. Here is a San Francisco Felucca which used that rig and they dipped the yard around the front of the mast by pulling the yard vertical and taking the sheet around the front and usually jibed instead of tacking. With no shrouds, this is easy. With shrouds, the yard must be slung outside the shrouds for this to work, and not between shrouds and mast like NINA, and this causes chafe issues. With very large yards, I doubt they were ever dipped and were hoisted inside the shrouds. One reason for forward leaning mast is it gets the sail area forward while keeping mast weight and strain back in the wider and stronger part of ship.
Here's an interesting historic link about lateens in (hotly debated) history.
http://books.google.com/books?id=Ww...cQ6AEwAQ#v=onepage&q=dipping a lateen&f=false
Excellent discussion and I'm sorry I was so passionate since you make a very thoughtful argument and really think about things.
Reason for dipping lug being good was great power to windward, very cheap, leaves boat open for fishing, very cheap, oh, and cheap since no jaws, boom, hoops, second halyard, shrouds etc. Luggers used mostly in areas of steady winds and where not much tacking was required. Places like Polperro with the wind blowing right in the harbor, used gaff rigs so they could beat out. The 18' lapstrake boat I had with a dipping lug and 1000 pounds of stone ballast could outpoint a Cal 20 if he did not have new sails. Very weatherly and strong pulling, but not right for most boats.
All square sails have gear to pull them up to the yard, what you refer to as brails. Older ones used removable sections from the bottom, the "bonnet" and the "drabbler" to reduce area. GOLDEN HIND (English, North Atlantic) had no reef points and did not reduce sail from the top in 1579. NINA has no ratlines, no footropes, no reef points and sail is either set or not, being gathered by the leeches and the martinets. The square sail revolution happened in the 1600s and most modern gear was in recognizable form by 1750, ratlines, reef points, buntlines, leechlines etc.
Mystic Seaport does focus on east coast US vessels, but the library has incredible resources and when I was a rigger there we were required to spend 4 hours a week researching and I read widely about the ancients once the MORGAN and such got boring.