How we minimize broaches / roundups

[krawall]

Hi all,

I thought I'm going to share this with you as it took us close to 3 years to figure this one out. We are learning every time we go out.

It's about our 36i and it would apply to most similar or smaller sized boat which, like ours, aren't very stiff.

We did have our fair share of broaches over the time. I guess it's just a tradeoff for light wind performance vs. stability and our 36i is on the tender side anyway, but we learned a few things that really made a difference.

a) it's not the main that makes us round up most times. The only times the main causes a broach is when there's a strong sudden gust and we fail to ease the sheet. But there are times when you ease the main and it's all the way down but you still round up - our solution: reduce head sail area before reefing the main! As counter intuitive as it sounds, I think it has to do with the bow getting dug in and hence the rudder coming out and we lose steerage.

So nowadays we reduce headsail area first and have much less roundups. It's also much easier to reduce head sail area!

b) we take more notice on where people are sitting. It's not "just hiking on the windward rail", but we do make sure that people sit as far back as they can if we are hard pressed. So the most heavy guys will sit on the rail but as far aft as possible, the lighter guys sit further forward.

Again, this lifts the bow out of the water and submerges the rudder deeper, giving better steerage.

These two things have helped us a lot and it took us years to figure out! If figured it from a friend when I asked him when he reefs his main and his answer was "Never! We only reef our jib!". So we gave it a try and it works! Though of course we still reef the main if we really need to.

This also helped us to win our class in the Rolex China Sea Race!

Cheers,

Tom

[tedp]

The funny thing is that in my SO32, when running with a strong wind abeam, I found that taking a roll or two in the headsail will relieve the rudder as well, so that checks with your observations. With our shallow draft, we suffer from the rudder lifting out sooner than a deep keel boat like the SO36i.

[MartyB]

Which also goes with racers that have multiple head sails will usually go down from say a 155 to a 140 to a 110 before taking in a reef! Same difference as putting a role or two in a furling jib!

The weight issue is also a pretty common thing to do when racing. Light winds get the crew forward, ass out of the water, as the wind picks up, crew back to help relieve weather helm among other things. If running, to get the bow up so one can plane to a degree.

Marty

[tedp]

I wonder what it would take to get an SO32 to plane....

[davideso37]

Re the broaching advice we do like to change down the genoa and keep the full main for a long as possible. We find that dumping the main quickly is important as once we start to round up it takes a lot of effort and rudder drag to bear away.
Recently I had some modifications make to my large genoa where we added carbon tapes to the leech to flatten the exit. Not only did it stop the draft moving aft but since the changes I have several times commented to the crew that the tendency to round up appears to have been reduced and we are sailing with a bit more heel. This fits the general thesis put forward by Tom. Shorten the genoa but also make sure the aft of the genoa is not hooking.
Just on the genoa changes the sail is a tape drive and it has proved so strong that we were carrying it into stronger wind ranges. We added 14 full length carbon tapes to the sail starting at the leech and the improvement was dramatic. The carbon has much less stretch than the kevlar tapes. The sail was three years old and I think it will now be first rate for another three.
David

[MartyB]

Ted,

I think your SO32 will plane quicker than my Arcadia! Not sure I have gotten it to plane but have hit 8-9+ knots with the spin up. Hull speed is 6.7 or there abouts. We hit 11.2 in a 40 knot gust, main and 110 up going down wind, with a 4' wave surfing! I'm sure the actual speed was higher, as we were also being driven by a current. That was a hoot of a ride!

Marty

[shiook]

And I keep the forward water tank empty as was suggested in the forum - that too helps.

[lateron]

Good advice Knowall.
I've been experimenting and found my SO32 sails faster with one reef in the main in winds gusting over 22k, but I accept that reduction of the headsail also works. Glad to say that since I put the mainsheet in the cockpit I can so easily be in control of the main in gusts and dump it quickly when required.
So far I've reached 9.2k SOG [ can't trust my log ] in 24k wind with tidal help of 0.6 k, so approx 8.5k through water on a broad reach no help from waves.
Our problem with weight distribution on the SO32 is we only have one water tank and it's right up front. I may try and find a home further back for my spare anchor. Also my cruising chute is at the mo up forrard.
I don't sail with any useful fat people so can't think of how to achieve any further weight redistribution. Any suggestions?
Ron

[renegade27]

Interesting that the focus is on the jib...

I also found a HUGE improvement by flattening my jib (genoa/ 135%). Simply by moving the block back, all the way in my case, I've been able to point much higher and cut the roundups to almost none.

I think that standard sailing theory is that by reducing headsail first, you shift the center of effort backwards which should INCREASE roundups (more force behind the keel pivots to weather)....

so the theory that you want to keep the bow from diving makes good sense - not about the CG of the sails... also would explain the amazing improvement seen by shifting the lead block backward to flatten.

I've also noted that more than any boat I've seen, my SO35 (shoal keel) is extremely sensitive to weight distribution forward/ aft. Sitting at the dock, we can see the bow dig in/ lift out of the water by 3 inches or so depending on the state of the water tanks, anchor locker and people aboard.

More credence to the theory!

All I know is that now, with the jib block further aft, I hold my own vs other weekend warriors upwind in a blow and have only rounded up once or twice when the wind picks back up (rather than every 100 yards!)

[lateron]

Hi Krawall...............sorry but a combination of not wearing my glasses and early morning bleariness led me to read your name as 'knowall' .......so hope I didn't cause any offence. Time for my annual check up at the opticians!!!
Cheers Ron

[MartyB]

renegade,

that is another common rig adjustment if you will when sailing in different wind conditions. Move the blocks forward in light winds, aft in heavier winds. Hence why I have not figured out why daysail/cruisers do not seem to want to put line control cars on their ib/genoa cars, makes it easier to adjust from the cockpit vs haing to go forward on the lee side, pull a pin, kick back/forward the car and reset the pin. hope that works, then when it does not, do all over. Also with roller furling, line adjustable carrs should be a given, as the car will need to get moved when you reef the jib too!

Marty

[ianqv]

Fab thread!! some v interesting reading.
I'l try reefing the genoa first next time!

Many thanks

Ian

[davideso37]

More roundups.
We sailed our SO37p in 20 knot plus last Wednesday with an occasional gust to 27 knots. With full main P = 13.6 m E=4.8 m and a 130% genoa we handled the gusts fairly well by dropping the main and driving on the genoa alone. The only problem came when we needed a bit more mainsail leech tension to get some height and we overdid the mainsheet tension. Two roundups which cost us 22 seconds but not bad for a windy day. If we were cruising we would have had two reefs in the main.
David