Spreaders? What do they do?

We reworded to say this Spreaders are rigid structures attached perpendicularly to the mast. The act to strengthen the mast in conjunction with the side stay wires (shrouds). Does that help considering the associated image?

To dive into the physics of it just a little bit (certainly more than is necessary in the module content): If you picture the tall mast and relatively narrow hull of a boat without the spreaders, with the shrouds stretched directly from the tip of the mast to the sides of the boat, the angle of those shrouds is pretty narrow (i.e. near vertical). You can probably see intuitively that this isn't ideal. In the unrealistically extreme example that they were *completely* vertical, you can probably see that they'd contribute no lateral force at all, which would do nothing for stability. What would be better is to spread the base of those shrouds out much further. The problem with that is that the bases would have to move well outside the bounds of the hull itself, so that's impossible. What the spreaders do, placed somewhere in the middle, is "artificially" widen that angle closer to the top of the mast. The physics works out such that this gives you (most of) the benefit as if the shrouds were at that wider angle all the way down. It gets even better: if you look at the picture, you can see that the spreaders also provide attachment points for other cables that look a bit like mini-stays connecting the tip of each spreader to the point on the mast where the next spreader up is connected. These "diamond wires" give us that same "wider angle" benefit along each segment of the mast, making it much more rigid against lateral warping in the *middle* of the mast. All together, this brilliant engineering provides stability and rigidity several times higher than a single pair of shrouds without spreaders could do, even if they *could* have that impossibly wide base.