why is the mainsail foot is so short?

[noonmark]

Can anyone explain why the mainsail foot is so short? It always seemed odd to me that the mainsail clew (sternmost attachment point, thanks google) is over a foot from the end of the boom. I've had someone ask me if I had the right mainsail on it. If the CP-19 has been faulted for anything its that they can be under sailed (esp the mk1 (sans bowsprit) like my 83), it would seem this could be an opportunity to gain a few extra square feet of sail.

I'm asking because I need to replace my decades old main after storm damage last fall, and figured it would be a topic worth exploring. Sailmaking recommendations also welcome!

[Salty19]

The boom is a good compromise as the roach of the sail will extend the sail out further than what might be apparent.  The roach needs to easily clear the backstay, which it should under any condition.  Also the boom end block and sheet need to swing past the aft rails with clearance.

Another issue to consider is the outhaul. I use a 3:1 outhaul with camcleat and the room between tack of sail and purchase point is tight.  Doable, but not much room for a longer sail foot.  If you go with a loose footed main (and I would suggest looking into it), you want the extra purchase of the outhaul 3:1

With this said, I'm sure you could go a little bigger if you measured carefully, but if you want better performance, a boom vang is a must and a full batten, loose footed main is not a bad combo.   

Maybe add that bowsprit and enjoy the larger headsail too?

I'm running a 110% (5.5oz) and 140% (5 oz) on the furler, a 170% nylon drifter (1.5oz)and a loose footed, fully battened main (5.5oz).  Conditions here are not too consistent---sometimes little wind and often too much of it.

I like National Sails.  Good value overall---nice sails for a very good price.

[Vipersdad]

Call Dirk.   http://nationalsail.com/

V.

[Damsel19]

Balance:
The main sail is sized to the boat. The addition boom length makes the sheet angle to the aft end of the cockpit closer to 90 degrees helping keep the sheet clear of the cockpit.
Its a compromise.
Extending the foot and roach will cause the sail to rub the back stay, but much worse it will increase the weather helm.
The bow sprit was added to reduce weather helm.
We have 135 for light air and do well. A 150 could be a good investment if you sail in light winds alot.
Fully battened loose foot main would be my preferred choice.
When the breeze picks up we reef the main before changing jibs. The helm and excess heal drop right off. She loves a shortened main. (we sail a mk1)

[Finbar Beagle]

To save me from myself