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Message: <blockquote data-quote="JohnSnow" data-source="post: 4168200" data-attributes="member: 32164">Sweet! A nautical discussion! I've got a bunch of fantasy ideas I've been kicking around for this, but first, a little discussion on the physics of sailing ships.The earliest form of "sail" propulsion is the square sail. It's pretty easy: you hold up a sheet to catch the wind and you're off in whatever direction it takes you.Slightly more advanced, you design a hull that resists lateral movemen (called "leeway") in the water. This is usually done by means of a centerboard or keel. Now you can sail at angles to the wind.Even more advanced you come up with a sail that, rather than catching the wind, cuts into it at an angle. A sail like this lets you sail at angles to the wind and, even moreso, allows you to actually sail into the wind. Sails like this are referred to as "fore and aft-rigged" or, in western Europe "lateen-rigged," because it was a common type of sail on Arab dhows (7th-century), which were common in the Mediterranean. Those boats could theoretically sail into the wind (at an angle of about 70 degrees), but 90 degrees was more common. The problem wasn't the rig, but the hull, which lacked a decent keel to resist leeway. For the record, the sail itself comes from the east, and is older than Caesar's Rome.Elsewhere in the world, a good hull with a shallow keel that prevented leeway could be found on Viking longships (9th-century). Combine these two pieces of dark ages (or even ancient) technology, and you have a truly modern sailing rig. Interestingly enough, that's something that wasn't developed in Western Europe until the 18th-century, and even then only on small craft. That rig was the lug, of which the Chinese junk is one example. And the Junk rig goes back over two thousand years...not 400.The problem is that windward sailing in an early fore-and-aft rigged boat (such as a lug or lateen rig) is hard work. it requires one to lower the yardarm (the pole at the top of a sail) and shift it to the other side of the mast.  That's hard work.In the 17th-century, the Dutch came up with a better way. They replaced the long yard arm with a shorter one that attached to the mast. That way, the sail could swing back and forth  without having to be raised or lowered. Later a boom was added to the bottom of the sail to stabilize it.This sail is well-known as early as the 16th century, and was used as the spanker (aftmost sail) on galleons from then on. Unless the mizzenmast was truly fore-and-aft rigged (which some were), every square-sailer carried a spanker.The point to all this is that advanced sailing ships coming late was an accident of history. None of the technology is terribly advanced, until you start trying to make certain kinds of rigs work on boats they aren't appropriate for. For example, the rig of a common sailboat (the "bermuda" or "Marconi" rig) is inappropriate on boats over 40-feet. Yes, we can make them now (up to a point), using modern materials. But pre-modern materials and manpower doesn't allow those kinds of sails to work on big boats.Using traditional materials, any boat over about 40' needs to be rigged with either multiple for-and-aft sails (gaffs, lugs, and lateens are common), square sails (on one or multiple masts), or, often, a combination of both. The reason you need multiple fore-and-aft sails is that for a single small sail, the pressure is insufficient to drive the boat, and for a sufficiently-large sail, the forces in tacking and jibing will cause the mast to break.Finally, a word on the "crew complement" of a ship. The normal crew to handle a 16th-century English race-built galleon was about 7-10 men. The "crew complement" gives you enough men for watch-keeping (meaning the boat can sail all day and night) and taking the ship into combat (when a cry of "all hands on deck" would go out).I've actually pondered a set-up whereby sailing vessels are considerably more advanced than they were in the European middle-ages, and more comparable to the vessels of the 16th, 17th, or even 18th-century. It doesn't require a whole lot of shifting, just an older civilization, of the kind highly suggested in D&D.On the other hand, square-riggers just look so cool.  <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f60e.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":cool:" title="Cool    :cool:"  data-smilie="6"data-shortname=":cool:" /> All this is totally off the topic of Spelljamming and astral galleons, but I think one can make a more advanced nautical technology work in-game without having to advance the whole setting to the industrial age.On the other hand, if you have a ship's wizard, who cares where the natural wind is coming from? <img src="http://www.enworld.org/forum/images/smilies/devious.png"  class="smilie" loading="lazy" alt=":]" title="Devious    :]" data-shortname=":]" /></blockquote>

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