C-Dory 16 handling concerns

[jbrosecity]

I have a question about C-Dory 16 handling. I searched the forum using different keywords and the most relevant topic I found was this topic entitled 'Chines and tracking' from 2007:
http://www.c-brats.com/viewtopic.php?t=6760

Obviously I am not the only C-Dory owner who has experienced the very discomforting sideways slip and slide in a following sea. I am talking about freshwater use and a mild sea state or chop, NOT big ocean swells. My wife will not even take the helm in these conditions, and while I can deal with it, I find it very uncomfortable. I believe the nautical term is 'yaw': To swing off course because of the force of following seas.

Where I and others in this thread seem to find it most discomforting is a following sea off the port or starboard quarter where the yawing motion coupled with some roll makes the little boat feel very squirrely. I have owned many different power boats from 16 to 22' and a handful of sailboats, and have never experienced anything quite this discomforting. I have experienced some broach in a following sea, but nothing like this yaw and roll.

This quite some discussion in the 'Chines and tracking' thread about different ways of dealing with it:

1) trim the motor up and go fast enough to stay in the wave. (I find going more slowly is less nerve wracking than going to fast in these yaw and roll conditions.)

2) Someone suggested using a 'steering ball' and the name Edson. I found the "EDSON MARINE
ProSeries Steering PowerKnob" on westmarine and while I could see this being useful on a steering wheel that is hard to turn (mine is not), I cannot for the life of me see why how this would be helpful in making the constant small corrections necessary to steer a straight course in the following sea.

3) There was some discussion of adding chines, a skeg or bilge keel. This is something I had thought of myself, much like the skeg on a waterski which helps it track straight and not slip sideways. There was much advice against this sort of modification in the thread.

I have not found the hydraulic trip tabs to be of much use for this problem. I would love to hear from other CD-16 owners and they handle these conditions.

Thanks a lot.

[MikeR]

Yes, I've experienced what you describe, but I suppose different people have different comfort levels, and I personally don't consider it a "concern" with the boat design at all. The C-Dory 16's are very small and light weight boats, and you need to take them for what they are. My solutions are 1) don't go out if wind wave forecast is more than 1-2' (preferred solution) and 2) if I do end up getting caught out in rough stuff, I will tack back and forth across the bay, like a sailboat would when going upwind, to avoid riding in uncomfortable directions, and 3) if possible, duck into a harbor or a bay and wait it out if the forecast is for winds to die down later in the day.

Like you, I've had many different boats over the years, including other 16 footers. One was a much heavier, wider, and deeper-v than the C-dory and didn't experience this, but then again it was a completely different type of boat (which also had several other drawbacks the C-dory doesn't). The other 16 footer, a classic Ed Monk-designed 1956 Bellboy, was similar in weight and beam to the C-dory, and also had a flat bottom and it behaved similarly, if not moreso. Just remember every boat is a compromise, and a 16' dory hull may handle much differently than other hull designs of similar size. But, do those other boats have a hard top, a sleeping berth, run efficiently with only 40 hp, and tow behind a 4-cylinder car? Probably not.

-Mike

[Marco Flamingo]

1. Trimming the motor up depends on the balance of the hull, your speed, and the steepness of the following sea. Even whether you have a 3 or 4 blade prop can make some difference. The "surfing" effect happens slower with 4 blade if you are allowing the waves to run past you.

2. Steering balls are as useful as they are in cars. Do you have one in your car?

3. Skegs are useful on water skis and surf boards. If you want to surf, you might want one. Chances are you don't want to surf. In fact, the sideways slip and slide is probably what you don't want.

I haven't had my 16 out in big enough stuff to surf very much, but I have done some scary surfing in boats over 30'. It's a creepy feeling. The easier a boat is to plane, the quicker the surfing ability becomes apparent in following seas. In situations where my 16 could surf, I run the trough (usually between 7 to 10 knots) and when I feel the stern lift in the "here we go" position, I throttle back and let that one go under me. It's often possible to run the angle of the trough at 12-15 knots, but if a following wave catches you, then you really have to throttle back at just the right time. Usually not worth the risk, especially if you have a superior officer (the Admiral) on board.

Of course, all of this is talking about a following sea of 4-5'. After that, you need to slow down and take yer whippin' for being out in those conditions.

Remember, it's a 15" 10" boat.

Mark

[davidJ]

I have a C- Dory 19, but I'm pretty sure your problem is you are trying to run with your hydraulic trim tabs down to far for the conditions.

When your tabs are down they force your bow down, with the bow down it requires more force to push it forward. So the following waves and engine tend to push the boat off to the side, resulting in the squirrelly handling you are experiencing. Trim up to get rid of the squirrelies and you will be able to go much faster than the waves.

You can also get the squirrelies when running into waves with your trim tabs down if you are going too fast. In this case reduce tabs or slow down to get a more stable ride.

[AstoriaDave]

jbrosecity,

I see you are from the Portland area. Bet you are running on the Columbia quite a bit, also my home waters. [EDIT: Oops! Checking your web site, I see you have been in FL this spring. Hope this advice is still pertinent. Are you back in the Portland area now?] We often have short period windwaves on the river, from sustained wind working a good fetch. And it is tricky to "ride the back" of one of these short period wind waves, where broaching is minimized, because they reform, putting the hull on the face unexpectedly.

If you are forced to run with the waves, about all you can do is ride the throttle, as others have described, and back off when you feel the boat "take off," preventing a broach or prebroach condition, and then get back on it as the windwave passes underneath the hull.

Otherwise, alternate tacks, running across the windwaves in a trough as much as possible, until you run out of sea room, and then switch around and run the other direction. This "tacking" method will minimize the broach, exchanging it for more roll, and prolonging your time getting home.

Finally, if you are able to, consider running in whatever lee there might be, to get out of the worst of the chop. This is only feasible if the more protected route is in sufficiently deep water!

[jbrosecity]

Good morning and thanks to everyone for the helpful replies. I will try to address the various suggestions and posts in this single reply. First, let me be clear, we do NOT have the trim tabs down in these conditions. Matter of fact I haven't really figured those things out too well and generally leave them in the up position. I know they raise and lower the bow. but I prefer to handle that with motor trim. I have the Marine Dynamics Hydro Tail Stingray (whale tail) installed on my Honda 50 and that seems to do a lot to affect trim using the motor tilt or trim. I had one on my 250hp I/O as well and it made a believer out of me for faster planing.

What I did NOT experiment with was to trim the motor way up in a following sea. I will try that next time. Again the “following sea” I am talking about is 1-2’ wind chop on a lake (exacerbated occasionally by larger boat wakes). In 4-5’ seas as one reply mentioned, I would not be out there unless caught suddenly in high wind conditions. I watch wind forecasts pretty carefully. Perhaps with the motor trimmed high and more speed I can stay up with the majority of the chop and experience less yaw and roll. But again the big yachts can create some pretty large wakes rolling across the lake so it is not always very consistent.

I definitely have tried to stay in the lee of any shoreline when possible but if running across an open bay with the wind chop behind you, there is often no lee shore to take advantage of. I also tried a bit of tacking rather than a more direct route to stay more in the trough and minimize the broach. I know a lot about tacking as we also have a Catalina 22 sailboat which is our primary water activity. And when running her with a following sea, I have had plenty of experience with broaching and have to work the tiller to maintain my heading. However at 6 kts (hull speed), the broach results mostly in a bit of weaving and regular minor corrections with the tiller... and not the disconcerting CD’s yaw and roll which is more like *careening* left and right. With the CD, I have found that if I go slow like my sailboat at 6kts or so, then the broaching is more or less benign and simply requires constant small corrections with the steering wheel like I do with the tiller. But it is the higher speeds that both the “admiral” and I find nerve wracking and which I was hoping to resolve.

It doesn’t sound like there is any percentage in trying to find some sort of skeg in increase lateral stability. It sounds like ‘riding the throttle’, looking for a lee shore. or perhaps tacking back and forth are the only “solutions” if the motor trim doesn’t fully alleviate the problem.

Question: I outweigh my wife by 2:1. We try to load the boat to compensate to some degree and I make sure she sits all the way to the outside and I tend to sit toward the inside behind the wheel. The boat seems to run mostly level, but we have considered adding maybe 75 lbs of weight under her seat to balance it out. Any thoughts on this?

Marco asked “Steering balls are as useful as they are in cars. Do you have one in your car?” Answer, not in my Chevy Suburban, no. But I had one on a volkswagen bus once upon a time and found it useful for wheeling a fast turn like in a parking lot. As I said, though, it doesn’t seem to me they would be of particular use for the kind of minor corrections necessary in the broach/yaw/roll. If I am wrong, then please, by all means, explain how one helps.

AstoriaDave asked if I was talking about the Columbia... and the answer is no. Yes the Columbia is home turf but we’ve been on the road a couple years and I bought the C-Dory in Florida from a guy who used it primarily on the lakes and rivers. I wasn’t really planning to take her back out west. As a matter of fact I was thinking of posting to the forum as well as Craigslist and boattrader and offering her for sale after concluding our summer in the 1000 Islands on the St Lawrence in September. Since I know how rare they are, I was hoping to make a quick sale in mid September. If anyone knows of an interested party they can contact me direct.

Thanks to everyone and I look forward to any other ideas anyone may have.

[spuncopper]

Hey jbrosecity,

Here's what worked for our weight distribution between my wife and me. She weighs approx. 120 and I weigh approx. 180. I mounted my house battery under the port side seat box. The battery plus the cable runs put us on a pretty even keel.

With a 4 stroke, 50 hp Suzuki weighing 242 lbs, 12 gallons of gas and the starting battery the boat was already slightly stern heavy. I didn't want to add anymore weight to the stern so this worked rather well.

Be safe out there.
Spuncopper

[Marco Flamingo]

>The boat seems to run mostly level, but we have considered adding maybe 75 lbs of weight under her seat to balance it out. Any thoughts on this?<

That is about the weight of a Group 24 battery, probably what you have on board. I moved both of mine under the passenger seat, which balances and evens out my 16 when solo (no need for trim tabs). But even with my wife aboard, the boat is balanced better than having the batteries in the stern under the splash well.

Steering balls don't help, IMHO (didn't make that clear). I used one for one trip and didn't like it. Fine for a tractor, but the steering on the 16 is plenty fast enough, so that's not a solution and I'm not even sure that you have a problem.

It sounds like the boat is just livelier than you are used to, especially comparing a dory to a sailboat. The CD 16 is light as a cork, shallow draft, no ballast and no keel. It might feel like it is sliding a little sideways with a quartering following sea (and there might actually be some lateral movement), but that is just the nature of the hull design. Nothing to be too concerned about unless the wave tops are approaching eyeball level (assuming that the speed is appropriate).

The CD 16 is my first cruising planing hull. At first, it seemed crazy fast, noisy, twitchy, and maybe unsafe. Nope, not at all. I've learned that that is just the nature of the beast. It's the sports car version of a cruising boat, both plus and minus.

One improvement over sports cars that I've owned is that when it rains I can keep dry in my C Dory.

Mark

[spuncopper]

Marco Flamingo... that was well said and I agree 100%! :lol:

[bmacpiper]

Hi there Joe!
Funny that I happened on this thread today--I was the author of the original thread you linked to from 2007. It was a good look back on my C-Dory adventures, and how much I've learned since then!

A few things.

First of all, I agree with most of what has been said here. The best defense is the weather forecast (including how the forecasted wind direction interacts with the tides). If that fails, staying on the back of a wave and being quick on the throttle and steering is next best. The trim tab piece is true, but not something I had on my 16, so I didn't consider it then. When running with a following sea, my later dorys have taught me that you want to have the bow high; in a boarding sea, drawing the bow down into the waves can make the ride a lot more comfortable, and doesn't cost a huge premium in fuel in my experience. A low bow with a following sea is definitely a recipe for bad things to happen.

Someone also mentioned surfing, and this always makes me uneasy, no matter how many times I do it. We have occasions where we have no choice but to surf a container ship wake if we want to go home, and all I can say is that we try to hit it well behind the ship (smaller), have the bow high, more or less perpendicular to the wave, and once you're over the top and committed, you have to put the hammer all the way down and steer through. Hesitate here and you will have a huge wall of water behind you waiting to make you pay. I would go well, well out of my way to avoid this situation, especially in a 16. This said, there are times that you can easily and confidently outrun the following sea, and this makes for a nice ride; I can't give you a good rule of thumb, but you will develop a feel for how much wave is "too much" for doing this. If it were me, 1-2' of wind wave would be the limit on the 16; on my 22, I'll do it up to about 3' with an occasional 4-footer. After that I slow down and move with the sea. Whoever made up the saying, "Fair winds and following seas" has never had 5 footers at their back in a 16!

As an aside, the slipperiness of the dory hull is one of its advertised safety points--so while it gets squirrely for sure, the upside is that when you make a mistake and broach, in theory the boat will slide sideways instead of "catching" and rolling. Having tried this out a couple of times (ahem), it worked for me, but I know I was lucky and was out in conditions too big for my experience and comfort levels--the boat looked after me.

Another thing I'd look at (for emergencies only, not as a planned thing) is a drogue. Take a look at Para-Tech Engineering in Colorado: http://www.seaanchor.com

They make beautiful sea anchors, boat brakes, and drogues, and have the experience to help you rig them. As luck would have it, I still have my drogue that is sized for your 16 Cruiser, and would be happy to send it along to you for the cost of shipping. It gets attached to the up-sea stern cleat and is set 2-3 wavelengths behind the boat. As you are riding the back of a wave or being slowly pass by the waves from behind (hopefully at 30 degrees or so), the drogue bites into the back of a following wave and prevents excessive yaw in the stern. In other words, if the waves are coming from your starboard quarter, the drogue would be attached to your starboard cleat and keep the stern from yawing to port as the waves push slightly from starboard. Have a look at the website and let me know if you're interested. I only had one opportunity to use mine after purchase--and then learned to be more savvy about what my boat could do vs. the weather at hand. The drogue will let you make an occasional mistake in reading your weather, with the knowledge that you will have some help getting home. Don't use it as a reason to go into more conditions than you or your boat can take.

Lastly, and perhaps most importantly--someone pointed out that this is a 15'6" boat. I've now owned your boat, a 19 Angler, and my current 22 Cruiser. With each one I've learned again, size matters. Here in the sound, I never went out in my 16 when weather was forecast to be 1-3' wind waves or bigger. In my 22, I routinely go out in those conditions, and we are generally comfortable unless we're fishing in 3 footers or something (and then it's an issue of comfort, not so much safety). With a following sea of 1-3', the 22 is easily able to plane and outrun the sea, and it's a joy of a ride--like it's on soft hydraulics--and would have been something of a white-knuckler in the 16'. I've yet to be in a big enough following sea in the 22 to make me uncomfortable, but see my point about weather above--my spidey sense is much more evolved these days and I don't typically "find" myself in such conditions like I used to. The one other thing my 22 has going for it is twins, which make a big difference as well. So when you add it all up, all the small things become a big collective--beam, length, weight, twins, experience.

All this said, I dearly loved the 16, it was my first "real" boat as an adult and we continue to appreciate the safety and stability of the C-Dory line.

Take good care and enjoy.
Ben

[thataway]

Two excellent posts by Marco Flamingo, and bmacpiper. The essence, is that the 16 is a very light and lively boat. Keep the bow up in following seas. Run at the speed most comfortable.

Recently a Rosborough 246 owner posted that hie Rossie handled so much better in following seas than a C Dory 22 he had owned. (I had often heard the opposite) I never felt that either of my 22's had any problems in following sea conditions--so I suspect that it is more the driver, than the boat. Any of the C Dory's is different. I drove a 25 last summer for a couple of days, I have been driving my son's 25 recently, Even the 3 25's I have driven, handled slightly differently:( load, power, trim) and they handle differently than the 22's do.

To use a drogue, I would suspect that one would have to go rather slowly. Handling any boat should become a reflex.. sort of like skiing, or biking....This reflex can range from the smallest sailing dinghy to a 60'+ cruising boat--or a ULBD racer....same with power boats--from a dinghy to an offshore racer to a trawler, in different conditions, different reactions and skills are necessary...

Balance, and bow up are key in the area, where you are having concerns.

[AstoriaDave]

jbrosecity wrote: It doesn’t sound like there is any percentage in trying to find some sort of skeg in increase lateral stability. It sounds like ‘riding the throttle’, looking for a lee shore ... [snip].

Yup. A skeg would likely make things worse. Flamingo and two others have mentioned that, though disconcerting until you get used to it, the slip to the side in lieu of a broach is a normal characteristic of a 16 as well as larger CDorys (but to a lesser extent).

You might want to hold onto that 16. Be pretty handy for quick jaunts on the Columbia.

[dotnmarty]

If you are keeping the boat, consider exchanging the whale tail for a Permatrim. Lots of discussion about them on this site. As for the balance, try to be patient. You will get used to the 16's "canoeing" characteristics and either won't think about them or come to enjoy them.

[Blueback]

[thataway]

I have not experience in the 16, and generally avoid commenting too much on this boat. However, my experience in the other boats, is that the permatrim, is more for getting the bow down--you generally trim the bow up--ou also want tabs all of the way up, when going down waves.

Handling heavy seas from abeam and aft the beam, is a lot of trimming the bow up--broaching is when the bow is down--and allowing the boat to naturally slip without tripping on a keel. Running in heavy seas down wind/waves, takes lot of skill in boat handling--both using the throttle, and wheel--a reason I run with one hand on the wheel--and in some boats have a "spinner" or "suicide knob" --and the other hand on the throttle. The off shore races have a throttle man and a helmsman--it takes one-man on the throttles to control those racing boats in these conditions...throttle is just as important as the wheel. All having enough power is important.

Would the Permatrim allow you to get the bow up more--yes it might. I don't know for sure in the 16--but I would also be shifting weight aft in those circumstances...