boat will not sail straight

Jul 27, 2015
45
catalina 30 SF bay
85 Catalina 30 standard rig. I am not sure how to describe my problem other than my boat doesn't want to sail straight. I was on SF bay last weekend and the previous weekend and when going to weather it seems the boat want to round up. I am constantly fighting the helm, when it turn to weather it takes a lot to bring it back on course and then it seems to fall off below course and as I correct it goes to weather again. If I hold the wheel to center as if on a constant course the boat will begin and continue to round up. this problem also exist on a reach as well. In lighter winds the problem doesn't seem as bad.

Also when motoring at a higher speed the bow seems to rise and the stern will drop almost to the point of the exhaust going below the water line. At slower speeds it seems fine.
 

Joe

.
Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
Depower your sails. Especially your mainsail. i.e. make them flatter. If they're stretched out and you can't reduce the draft, your options are to have a sailmaker recut the sail.... or... invest in a new set of sails.
 
May 17, 2004
2,099
Other Catalina 30 Tucson, AZ
What you're describing is weather helm. A little weather helm is a good thing as the action of the rudder creates lift which translate to power. Not knowing how your main and jib are trimmed makes answering your question somewhat difficult but the first thing that came to my mind was do you have a backstay adjuster and was it on? Mast rake will cause weather helm. Many Catalina sailors think that applying the back stay will bend the mast but it's not possible to bend a Catalina mast no more than it's possible to bend a telephone pole!! It blows like stink on SF bay and the effect of the wind and your sail trim ,whatever it is. is causing the problem.

Follow Joe's advise and if flattening the sails does not work induce some twist to depower the top of the sails.
 
Mar 13, 2011
175
Islander Freeport 41 Longmont
SF Bay is always a challenge. However, as Joe mentions you need to depower. Also, Mast rake will have an affect on your weather helm, make sure your rig is tuned correctly. You don't mention what size jib you are using (90%) is always a good one for SF Bay, at least to start, look at putting a reef into the main as well. You can ease the vang which will introduce twist in the top of the sail and allow the boat to sail with less heel.

More details on your sail configuration, and tuning will help to diagnose your issue and options
 
Feb 8, 2014
1,300
Columbia 36 Muskegon
And as for the stern squatting, that is completely normal as you approach hull speed. The bow is attempting to climb up the bow wave, but since it's not a planing type hull, it can't. If it bothers you slow down a little.
 

Ward H

.
Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
Brad,
What do you consider high speed for motoring? I can motor at just above 6 knots at about 2,800-3,000rpm. If I push the rpms higher I don't increase boat speed and the boat will start to squat. Normally I motor around 5.5 knots and do not notice any squatting.

Concerning weather helm, properly trimmed sails will take the pressure off the helm. As Joe and others mentioned, if they're stretched out to the point you can't trim them flat, it may be time for new sail/sails.

All last season and the beginning of this season I was struggling with weather helm in higher winds. I would reef the main and then reef the jib but always left the reefed main up. I could never get the boat trimmed to a neutral helm.

I just recently learned that when I can't trim out weather helm using the sail controls, its time to reef the main.
If I still have too much weather helm, I drop the main and sail on the 130% jib only. As wind still builds I then start to furl the jib.

The need to reef occurs earlier than I expected, which I attribute to the quality of my main sail. (It's newer but I think it was poorly built)

For main sail controls I work the mainsheet, traveler, outhaul and vang.

Hope that gives you a few ideas.

Ward
 
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Jan 1, 2006
7,039
Slickcraft 26 Sailfish
This has been posted many times but mast rake is not set by the backstay. It is set by the forestay length.
 
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May 17, 2004
2,099
Other Catalina 30 Tucson, AZ
There's forward rake and aft rake. The boat in question is a Catalina 30. If, for some weird reason, he wanted to rake the mast forward he'd use the forestay because that would be his only option. If he wanted to rake it aft he'd use the backstay adjuster. For the average C30 cruising sailor my recommendation is to not use the backstay adjuster. Keep the mast plumb straight up and down.

I had a primo Garhauer backstay adjuster Garhauer gave me a a gift - I never used it. Dock neighbors asked me why I had it. My answer was that it looked trick -- like fancy hub caps, which have nothing to do with the performance of a car or a C30.

Let's stick to Brad's problem with weather helm. Raking a mast is way beyond the expertise of the average sailor.
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
Brad, I sailed on SF Bay from 1978 to 2016. You have too much sail up. Period. I sailed a Catalina 22, 25 and our 34. I had a single reef in the mainsail from April to September and used smaller than 110 jibs.

Almost all Catalinas (if not most all boats) will turn to weather if overpowered. Call it a safety feature.

And boats with shaft drives will squat under power.
 
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Nov 26, 2012
1,653
Hunter 34 Berkeley
You’re getting overpowered causing the boat to round up. From the description it sounds like you’re way overpowered. When overpowered I start by easing out the main even to the point where it is almost flagging. You can also move the jib cars back. After that, reef the main. On windy days I will often sail main only cause I’m lazy.
 
Jul 6, 2013
221
Catalina 30TR, Atomic 4 2480 Milwaukee
Our boats have plenty of power. I reef the main when the wind is over 15 knots. Then I adjust the furling jib to suit the day.
I’ve also found that easing the traveler a bit reduces heeling and weather helm without loss of speed.
 
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
Brad, I sailed on SF Bay from 1978 to 2016. You have too much sail up. Period. I sailed a Catalina 22, 25 and our 34. I had a single reef in the mainsail from April to September and used smaller than 110 jibs.

Almost all Catalinas (if not most all boats) will turn to weather if overpowered. Call it a safety feature.

And boats with shaft drives will squat under power.
:plus:
I sailed my Catalina 27TR on SF Bay for 15 years. From April To September, we upwind sailed with a second reef and 95% jib ( equivalent to a 110 on a standard rig), which we frequently reefed by 10-20% (in linear terms).

when going to weather it seems the boat want to round up. I am constantly fighting the helm, when it turn to weather it takes a lot to bring it back on course and then it seems to fall off below course and as I correct it goes to weather again
It’s normal to have a little weather helm going to weather in 5 kts or more. In high winds, depower and reef the sails so that you can keep the boat at 15-20 degrees or so of heel. If your rig is tuned right, you should be able to steer a steady course with the rudder at 3 or 4 degrees of deflection with 15 degrees of heel. Don't try to hold a perfectly straight compass heading; as the wind strength and direction shift slightly, steer accordingly (unless, of course, you are racing and have attentive and active jib and mainsail trimmers)

First, Check the rig tune. Do a basic tune. For a Catalina 30 mast head rig with fore and aft lowers, and non-swept spreaders,: first, move gear so the hull is floating level fore and aft onher lines. Then Check that the mast is centered athwartships, no bends, and no rake, using a weight at the end of the main halyard to measure rake. If you need step by step instructions on how to accomplish that, get back to us for details.

Or read Selden Mast's booklet, specifically the section on mast head rigs. http://www.seldenmast.com/files/595-540-E.pdf

If the rig is tuned right you can depower the sails as follows. A)To depower the mainsail when sailing upwind: apply maximum outhaul to depower the lower section and Ease the mainsheet and let the Vang off to induce twist in the upper sections.. Lower the traveler to degrease the angle of attack ( but this will reduce your ability to point high). If you still can’t keep the boat under 20:degrees of heel, put in a reef or two. I used to go straight to the second reef with my C27.

Feather up in the gusts, don’t dump the main. Dumping the mainsail makes the boat lurch completely upright and then you need to start trimming and balancing from the beginning.

Make sure you have the backstay tight enough to keep the forestay tight in the gusts. A sagging forestay increases the power of the jib by making the draft deeper. Also, you can mover the Genoa car aft to induce twist in the upper sections of the jib, which depowers it.

Check the steering linkage. If the steering is sloppy, it’s hard to hold a course. Mark the center and 5 degrees of rudder deflection to port and to starboard. Also mark 45 degrees of deflection to each side.

Last but not least have a sailmaker look at the condition and shape of your mainsail and jib. Stretch baggy sails make a boat hard to control, because it heels precipitously in the gusts. If you can’t trim the sails so that the boat has good behavior from 5 to 30 kts with higher gusts, you need new sails.

PM me if you’d like me to take a look. I’m berthed in the Alameda Marine. I’m retired from sail making now, but maybe you’re close enough for me to take a look at your rig tune and sail shape. I could buzz over and take a look.

JudyB
Retired sailmaker
 
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Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
@Phil Herring
Phil, What just happened? I tried to edit my post #12 (boat will not sail straight ) to fix a few details, and the system told me I exceeded the 15 minute limit for editing. I’d like to fix some things that I wrote that might be confusing, misconstrued or in accurate.
Cheers,
Judy
 
Jul 7, 2004
8,402
Hunter 30T Cheney, KS
Our boats have plenty of power. I reef the main when the wind is over 15 knots. Then I adjust the furling jib to suit the day.
I’ve also found that easing the traveler a bit reduces heeling and weather helm without loss of speed.
I was going to suggest using the traveler also, along with previous tips.

Aren't C30's mast head rigged? Does an adjustable backstay do anything for rake.
 
Jul 6, 2013
221
Catalina 30TR, Atomic 4 2480 Milwaukee
I was going to suggest using the traveler also, along with previous tips.

Aren't C30's mast head rigged? Does an adjustable backstay do anything for rake.
Rake is controlled by the forestay. The backstay only affects the tension on the forestay. And as others have commented, the C30 mast is stiff, so it is nearly impossible to bend.
With a furling jib, I like the forestay tight.
 
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Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
Aren't C30's mast head rigged? Does an adjustable backstay do anything for rake.
On a mast head rig, tightening the backstay does not increase rake measurably. The mast is not flexible enough to bend easily. In terms of physics, Tightening the backstay primarily increases compression on the mast, and if the aft lower shrouds are loose enough to allow it, it will bend the middle of the mast forward a little bit. The mast head will not move aft more than a few millimeters, because the forestay will not stretch enough to permit it to move aft.

It the rig is tuned comparatively loosely, tightening the back stay will increase tension on the forestay, which will keep the draft of the jib from getting deeper and more powerful when a gust hits.

Racers may tune their rigs to be comparatively loose for light air days, so they can let the mast tilt forward if they need more power when going downwind.

Ps. @Kingjim91 answered the question whilst I was typing. He’s faster than I am!
 
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Joe

.
Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
Been reading through the responses in this thread and I'd like make this comment. Adjusting the traveler is not depowering the mainsail.... it is simply changing the angle of attack to compensate for changes in apparent wind direction without altering the sail's trim setting. Sorry for the nitpick.... just trying to add to the newbie's confusion, I guess.
 
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
Been reading through the responses in this thread and I'd like make this comment. Adjusting the traveler is not depowering the mainsail.... it is simply changing the angle of attack to compensate for changes in apparent wind direction without altering the sail's trim setting. Sorry for the nitpick.... just trying to add to the newbie's confusion, I guess.
I respectfully disagree.

If you increase the angle of attack of a foil, you increase lift. More lift is more power. Decreasing the angle of attack decreases lift and power.

Easing the traveler decreases the angle of attack without changing twist, so the flow remains attached to the sail.

Angle,of attack is defined by angle between the chord of the sailand the apparent wind angle . Chord is the line from luff to leech. Lift is generated perpendicular to the apparent wind direction. Drag Is generated parallel to the apparent wind direction.

Citations:
Tom whidden,, chief technical officer at North. sails.
Angles of Attack

Also see texts by c a marchaj and the works of Arvin Gentry.
 
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Mar 13, 2011
175
Islander Freeport 41 Longmont
So to add to the comments from DrjudyB and others, There are several ways to depower the mainsail, adjusting the traveler will keep the mainsail with the same airfoil but with less lift (assuming wind angle doesn't change), your essentially stalling the wing, Easing the vang, will allow the top of the sail to twist off, dumping wind and depowering the main, easing the mainsheet will also depower the main. On SF Bay if I'm slightly overpowered sometimes that works, you can depower the main a lot to the point of almost luffing, as long as its not getting backwinded by the jib. Of course the subtle changes to sail trim also help, cunnigham, outhaul, etc. by flattening the main and reducing the size of the airfoil.
All of these mainsheet, traveler, vang, cunningham, outhaul, , halyard and leech lines. affect sail trim which affects how much power is provided by that specific engine (sail). We then have to add in all of the similar controls on the jib (don't forget to add in jib car position), along with rig tuning, rudder balance and position and placement of people, ballast and other stores, to get total control of everything and then you can make the boat go where you want to go. Did I also forget to add in wind, waves and current to the equation. It sounds very confusing and no I haven't figured it all out (I add in a Mizzen sail to my equation), but that is the joy of sailing, its a constant learning process.

On SF Bay, go out early before the summer winds pipe up, head towards the southbay and get in the shadow of the bay bridge or Treasure Island where it is a bit more protected. Practice, practice and more practice and then head out into the main part of the bay. Figure out what works for you and your boat and don't worry as long as you keep the people in the boat and the water out of the boat your doing just fine.

Fair winds,
 
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Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
Just a correction to Joe's terminology. When you ease the mainsheet of traveller so far that the sail has 0 dgrees of attack and it does't produce any lift, that's "luffing", not "stalling."

Stalling is what happens when you oversheet the sail, or saii "too close" to the wind. The angle of attack increases until the air flow detaches, from the sail completely and suddenly it' can't generate any lift at all.
 
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