Arguments for windward canting:

    - Vertical lift can partially offset heeling moment.

    - Vertical lift will reduce wetted surface area.

    - Boom end is more accessible when over the deck.


  Arguments against windward canting:

    - Booms want to rotate towards the deck in light winds. 

    - Sails want to flop down as well, in beating or close reaching, even if the booms are somehow tied out.

    - Boom end is more of a hazard when over the deck.

    - Harder to winch a MOB on board if using the boom.

    - Recovery from a knockdown will be harder with the ww hull past 90 degrees.

    - Exposed sail area increases, not decreases, as the boat heels or flies a hull.

    - Vertical lift aft of the center could actually slightly increase pitching moment.


  I was a big fan of the k-proa at one time, with mast severely canted to windward, but was later convinced that this would only work with consistent trade winds and a crew that could dump sheets at a moment's notice. 

  Flying a hull on my cat still scares me after ten years, but at least things slow down as the boat tips.  I couldn't imagine the mast accelerating towards the water as the hull starts to fly.

  That would be less of an issue on an HP with a single sheet (perhaps with a fuse), but I'm just as concerned with light wind performance and capsize recovery as I am with the heeling-acceleration issue, so I'm now a vertical mast convert.

        - Mike

 

In the diesel electric thread that is going on, there is some mention of harryproas running slightly bow down under sail, and how a schooner rig might help.

This made me wonder why the harryproa masts are not canted slightly. It would seem that a 10 degree cant to windward would provide some lift and would also make the lw hull structure a bit stronger.

I am thinking that it helps structurally since it would provide more lw area at the deck and more ww area at the base, which are the two highly stressed areas under load.

So why aren't the harry masts canted? Does this lose too much sailing performance in other ways?

- Gardner