whats the best design for cruising??

[MikeJohns]

Originally Posted by sharpii2

................I think it is dangerous to imply that better designs would have been able to get through that unscathed...........

On the contrary It's pretty indicative of just what attributes you want in a blow offshore.

Also remember that the 'heavy' full keel that sank was actually a performance boat itself, light and unstable for an ocean cruiser of her day (over 45 yrs old) (AVS 124 deg DL 260) even then her loss was due to her construction not her hullform.

Note the contessa 32 on that chart.

It is pretty clear that the UK regs for unlimited offshore was pretty close to the mark for that event.

[rad...]

Hi again, thanks for all the replies, lots of usefull info there. I have yet another question to do with the hull shape itself. what are the diferences in performance between a hull with a chine (or multiple chine) and a smooth hull, as in a plate steel hull versus a rolled steel or fibreglass hull. my personal theory so far is the chine'd hull would'nt be as fast or comfortable as a smooth rounded type of hull. can anyone confirm my theory or totaly blow it out of the water.
Thanks for all the replies so far, please keep them coming, as my mind is slowly getting made up..... i'm nearly there.
Cheers. Rad...

[FAST FRED]

"I am a great fan of ketches; they are extremely popular with cruising folks, mostly because they subdivide the sail plan into smaller sails and more manageable sail set options for a wide variety of weather conditions.'

That's the common NA sales pitch but many suffer a severe lack of windward performance , tho many cruisers use Iron Mike to windward or in light airs .

The ride might improve with "Jib and Jigger" (doused mainsail) but your not going anywhere in a hurry, if at all..

For this old curmudgom a ketch is a great boat,

IF you fly a huge mizzen staysail , to get moderate performance in light air.

Or the mizzen is a nice backrest to use a sextant with.

But then I'm dating my self , sextants aren't even seen as table ornaments anymore.

My choice in a cruiser a CUTTER .
Same versatility as a split rig with far better performance.

I have never been on a boat , cruiser or "racer" where the ship was not sailed sharper in company, so performance does count!

Sure Sure "beating off the shore in a survival situation" might happen , but a sprint for the deep water in an anchorage is loads more common , and fun!

FF

[MikeJohns]

Originally Posted by rad...

....my personal theory so far is the chine'd hull would'nt be as fast or comfortable as a smooth rounded type of hull. can anyone confirm my theory or totaly blow it out of the water. ......

Actually I think chines are the shape of the future, well placed chines can reduce resistance, add a little to roll damping and considerably simplify both construction and repair. But poorly designed chines can add to resistance.

There's a lot of money being spent on testing of chine optimisation to produce better vessels with lower resistance than round bilge.

The key is in looking at the flow field around the hull and just how the chines can modify it and how they should be placed to ameliorate any tendency to vortex shedding . There are now some good guidelines.

But even the resistance caused by flow across poorly placed chines is generally not significant in the scheme of things, providing the hull coefficients are reasonable then other factors predominate.

In Australia there are a lot of chined metal displacement sail-boats and it's interesting to see for example virtually no difference between Adams performance cruisers of round bilge or chined construction. The boat with the better sails/ sail-trim is the faster one.

The bad name comes from back-yard designers knocking out cumbersome easy design 'boxes' with all the performance crippling features imaginable but it's not the chines that are to blame.