Quote Originally Posted by Dobbs View Post
Yes, boats with the fore and aft rig (like schooners) are faster upwind than down, and here's why...

We'll start directly downwind. A boat sailing directly downwind subtracts its speed from the wind speed. For instance, if the wind is blowing 10 knots when the boat is raising anchor, the crew (and sails) feels 10 knots. If the boat is able to sail directly downwind at 4 knots, the "apparent wind" (sailing term) that the crew (and sails) feels is 6 knots. As you can imagine, the boat ends up finding a sweet spot, but is always struggling with the faster it sails, the less wind is filling the sails. Fore and aft'ers are not as good directly downwind as square riggers, so I came up with the blue arc, which indicates the boat travelling at the next slower speed than indicated by the sail setting gauge.

Now, the other points of sail are more complicated (it's vector math).

If the boat is sailing on a broad reach (with the wind coming over the quarter), the boat combines its forward speed vector and the true wind vector, and gets an apparent wind speed that is actually higher than the true wind speed. In addition to math helping out, none of its sails are blocking each other either, like they are directly downwind. For square riggers, this is the green arc, because they are not really at their best trimming the sails in close (like fore and aft'ers do naturally). On a schooner, the crew has let the sails out to leeward, trying to emulate the square rigger's spread of canvas, but not quite able to compete. That is why I made that arc yellow.

Finally, the same math applies for upwind, only more so. The square riggers are stuck, because they can't trim their sails fore and aft, because the shrouds get in the way. The schooners are able to trim their fore and aft sails almost to the centerline, and that allows their sailplan to be more efficient upwind than the square riggers. That is why I have made that arc green.

I hope that helps and doesn't sound like pure gobblideeguck.

As a sailor in real life, I have made more historically accurate sailing arcs for all of my ships. It's probably not for everyone, it makes going to windward and tacking significantly more challenging (hope you never have to beat off a lee shore with one of my 1st rates). I came up with the schooner/cutter card to allow exploring Baltimore clipper vs. convoy scenarios. I also have a card for a brigantine (hermaphrodite brig), which is sort of a hybrid upwind/downwind sailplan.
Dobbs,

Your explanation makes some assumptions that I’m sure are correct, but I’ll never understand. Did you make allowances for a fore and aft rigged ship going wing on wing? (One sail to starboard, one sail to port)

If I’m running at full speed, the blue area tells me to use the battle sails arrow, but do I use the yellow or green arrow?

I thought the red area would be smaller.

Please send your other cards, I am interested in what you’ve done.