Boat handling characteristics

We recently moved up from a 28 foot express cruiser to a Mainship 350 Trawler (350/390). This has a single Yanmar.

She really doesn't plane, so we run at about 8 - 8.5 kts. After many years with planing boats, this is our first trawler. Tide and wave direction were never really a concern in out planing boats. About the only impact was whether it would be wet ride or a dry ride. We would take that little express out in just about any weather and we never thought anything of 6+ foot seas.

We recently took a trip in 2-4's which were quartering on our starboard stern. Many of them pushed the stern so far to port to that I hit the wheel stops turning to port to counter the action and stay on course. I soon realized that I was holding the wheel at around 25% to port to track on my course.

It occurred to me that 4-6's or higher could be a potential problem. avoiding going out in anything but perfect weather would be a big change in our mindset.

Are these handling characteristics normal for a trawler? Is this a mainship issue? What do you folks do?

If you are finding poor rudder action, like needing to bump against the stops, add some power. Can also just wait for rudder action to do its thing. Sometimes going to the stops is not necessary, as letting the boat respond to half rudder will do, eventually. Not possible to stop all wandering.

All boats have their peculiarities. I've run some Mainships, but not that boat in those exact conditions. Seemed to handle ok.

Hi Shrew, We have the same boat (300 Cat power) and similar handling. Quartering stern seas are the worst in these boats. Square on the stern is a little better but defiantly the worst trait of this boat. They have a very square stern and a lot of buoyancy due to the foam (or after recall, hollow) swim platform hull extension. Filling the water tanks helps a lot as the weight is far astern and running from the lower station helps lessen the effect but after 9 seasons with this boat, we have found no solution other than pick your days and try not to run long distances in anything other than head seas (runs great in head seas!) Happy Boating!

It helps to anticipate the boat's movement. When you begin to feel the stern lifting, turn the rudder just before the boat is turned by the wave.

The other option would be to alter course to account for the waves. There is no rule that says you have to steer a straight line to your next destination.

Quartering seas are not fun. Fighting the wheel for hours is exhausting. If there are small craft warnings and seas predicted to be 3-5 I'm apt to stay where I am unless I'm heading into them. RI Sound and Block Island Sound would be considered calm days at 2-4. If you can't add more power you need a real time feed for the NOAA marine forecast

Anticipation will be your friend. Learn the feel of the boat, anticipate the movement of the stern, and start correcting just before the stern starts to swing.

Changes in course is certainly an option that I have used. 20 degrees can make big difference

Despite all the brand allegiance and ownership pride you might hear...

Semi displacement trawlers or planing vessels run slow will roll, wallow and heave in the most moderate of conditions.

Live with the rolly polly world unless you have stabilizers.

Thanks folks. I appreciate the feedback. I suspect some of it is a learning curve. With outdrives and a wheel that turned 3 turns from full Port to Stbd (and at planing speeds) the previous boats required very little input from the wheel. Now with almost 8 turns of the wheel, I suspect part of it is the result of understeering and part of it is the result of late reaction times. As MarkPierce suggested, I'm trying to anticipate earlier.

Of course having a working auto-pilot would be helpful, rather hand-steering for hours at end.

SoWhat said:

RI Sound and Block Island Sound would be considered calm days at 2-4.

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Yes, this is really the root of our concern. I could count on 1 hand the number of times I've seen less than 2-4 in the last 10 years, unless we're in Gardiners Bay or Fishers Island Sound. (apologies for the local references)

We had a guy last year (claimed to be an 'offshore fisherman' who liked to run out to the Canyons) say, "If the forecast is 4 feet, I don't go out. My wife did a 'spit-take' with her beer (probably her 6th or 7th) and blurted "So, you're saying you don't go out???......no wonder you're always on the dock." (Ouch, b1tch-slapped him right in the ego).

Shrew said:

Yes, this is really the root of our concern. I could count on 1 hand the number of times I've seen less than 2-4 in the last 10 years, unless we're in Gardiners Bay or Fishers Island Sound. (apologies for the local references)

We had a guy last year (claimed to be an 'offshore fisherman' who liked to run out to the Canyons) say, "If the forecast is 4 feet, I don't go out. My wife did a 'spit-take' with her beer (probably her 6th or 7th) and blurted "So, you're saying you don't go out???......no wonder you're always on the dock." (Ouch, b1tch-slapped him right in the ego).

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Yes - we know the area well and had an early 34 Mainship which had similar speeds and rolling in those seas. We altered course often by 10-15 degrees to improve the ride even though it will lengthen the trip overall. Those seas and the currents in LI sound and BI sound make it even more important to plan your trips time with weather and tides in this area.

"Of course having a working auto-pilot would be helpful, rather hand-steering for hours at end."


In my experience the autopilots do not help in these cases as they have too much work to do in too little time. If you are in tightly spaced seas the autopilot cannot react until movement begins off course and then it will react too slow making some conditions worse.
Now maybe someone (please help) here knows of a newer autopilot or some other way to solve for this but that was our experience with slower trawler hulls in tighter seas.

To echo what others have said, I find that changing heading can improve the ride. Yes, you'll look like a sailboat zig-zagging to your destination, but it helps to smooth out the roll.

We crossed Lake Ontario last spring in quartering 4 to 6s. We have an older autopilot that isn't interfaced with the plotter, but does work well. We just left the autopilot on and lived with the hunting back and forth. It would take some time to come back onto course, but it did just about as well as I could have given the conditions. It was uncomfortable but not dangerous.

Also worth noting. Rolling is something that we were not surprised at, but definitely notice. We're not worried about the rolling. What I'm referring too is more like 'yawwing' where the stern decides it's in a race with the bow and is deciding it wants to make a pass.

We have long, thin channels which cut into the mainland here that funnel winds.

One thing we've done to cross a channel with the wind on our stern (if the next inlet or destination is sufficiently downwind) is to settle into the trough of the waves and match the speed of the waves (angling a bit towards the direction you want to go) then "ferry glide" or "crab" across.

Do you have commercial fishing boats about your size in your area? Our boat 'misbehaved' in straight downwind conditions until I learned how to do it properly by following a commercial fisher for a while.

I'd just get a better design but the better design will have anti-qualities you most wouldn't like too.
If you keep the boat post #5 is probably the amswer.

The more a boat looks alike at both ends the better it will be in following seas.

It's not really a trawler issue. I'd say the problem is mostly due to a square stern, but it's exacerbated by a smallish rudder and slow (8 turns?) steering.

Having no autopilot also magnifies the problem and makes it all very frustrating.

With 8 turns lock to lock, that is super slooooow steering. My rig is 6.5 turns an I am close to modifying to something more reasonable like 3.5-4.

smitty477 said:

"Of course having a working auto-pilot would be helpful, rather hand-steering for hours at end."


In my experience the autopilots do not help in these cases as they have too much work to do in too little time. If you are in tightly spaced seas the autopilot cannot react until movement begins off course and then it will react too slow making some conditions worse.
Now maybe someone (please help) here knows of a newer autopilot or some other way to solve for this but that was our experience with slower trawler hulls in tighter seas.

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Smitty,

Often pump sizing can make a huge difference in the ability of an autopilot to react quickly enough in following seas. The hard-over to hard-over times can vary substantially. In the attached chart you can see an example of this being from 7 seconds to 25 seconds on the same steering cylinder with three different pump sizes. The larger the pump, the faster the correction, but the more power it consumes. Most modern control units will proportionally vary the pump output voltage to compensate for larger pumps in lighter conditions. A good discussion with the manufacturer prior to your autopilot selection can make a difference in the equipment you end up installing and how it is ultimately configured.

Obviously 'Sea State', 'Sensitivity' or 'Power Saving' settings make a difference as well. In following seas, a tighter course will be kept if these are optimized.

Ski in NC said:

With 8 turns lock to lock, that is super slooooow steering. My rig is 6.5 turns an I am close to modifying to something more reasonable like 3.5-4.

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This is 'tune-able'?? Honestly, at the end of 2-3 hour run, I feel like I've been mixing a large bowl of cookie dough the entire time. It is exhausting.

Noahstvr said:

.... They have a very square stern and a lot of buoyancy due to the foam (or after recall, hollow) swim platform hull extension. ....

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I don't want to hijack the thread...but you could explain what was recalled ?

Echoing some prior posts - course adjustment can help. Additionally, play with speed. I've found that sometimes minor variations in course and speed can result in a remarkably improved ride. Don't be hesitant to experiment.

In my case, I have a planing hull, relatively small rudders, and a square as a brick transom. Aft, quartering seas can be difficult in terms of comfort.

Shrew said:

This is 'tune-able'?? Honestly, at the end of 2-3 hour run, I feel like I've been mixing a large bowl of cookie dough the entire time. It is exhausting.

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To reduce my L to L, I'm need to replace the rudder cylinder with one with a smaller piston diameter. Or a helm with more displacement per rev. One or the other or both.

It surprises me a production boat has 8 turn L to L. Are you sure about that? Maybe you have air in your steering. That would be an easy fix!!!

Sometimes it's beneficial to tack, much as in a sailboat, just for different reasons.

Also, I suspect you were running the Sea Ray faster. You need to learn to match speed to the conditions and timing of the waves. Often times a bit faster can help, sometimes a bit slower will. I would guess that if you ran faster you'd have far better control in those conditions.

Then as to autopilot. Tuned for those conditions it can do an amazing job. Better than you turning back and forth. The education aspect is learning to tune it and having a setting programmed for those conditions. Basically adjusting sensitivity.

Much of it is going to be experience. Don't scare away but learn to handle.

Then there are conditions that some express cruisers will handle better than some semi-displacement boats and even some trawler types. I've been a bit surprised to find many trawler type owners don't go out in conditions many express and other boat owners do. Part is not wanting the discomfort, but part is the response of the boat to certain conditions. Still, I'm confident you can learn a lot as to how to handle the conditions in your Mainship. Learn it's strengths and weaknesses and how to play to it's strengths.

BandB said:

Also, I suspect you were running the Sea Ray faster. You need to learn to match speed to the conditions and timing of the waves. Often times a bit faster can help, sometimes a bit slower will. I would guess that if you ran faster you'd have far better control in those conditions.

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This is something that I'm still learning. With an SD hull, adding power at some point tends to settle the stern. This can change how the boat rides in awkward seas. My reflex when getting in uncomfortable seas is to back off on the power, but I'm learning that isn't always the best approach.

dhays said:

This is something that I'm still learning. With an SD hull, adding power at some point tends to settle the stern. This can change how the boat rides in awkward seas. My reflex when getting in uncomfortable seas is to back off on the power, but I'm learning that isn't always the best approach.

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That's the natural reflex. I recall the first time our training captains had us train in rough seas, 6-8' in the Gulf of Mexico. We were in a planing boat. First impulse was slow down. In the hours of training that day we learned so much about timing and handling waves from all directions, learned to surf. We left far more confident and comfortable, but had they not been there we never would have run at the speeds we did. Every boat is different.

However, think back to rear wheel drive cars, the training of applying power rather than letting off to regain control in cornering. Well, your boat is rear wheel drive.

Greetings,
Mr. S. Ah yes. The old square stern situation...Mr. MM's post (#16) Brought back an old memory of running down Long Island Sound with a following/quartering sea just a day before a Nor'easter blew through.

As noted, our auto pilot was way too slow to correct resultant yawing so I had to hand steer for 7 hours. I might also mention this was the first day of a delivery trip with a new, to us, boat (34' Marine Trader) so the adrenaline was flowing and the pucker factor was high.

The swells/waves were just a bit too fast for our maximum speed so they kept passing under us and causing no end of "holy sh*t" moments. I figured if we could just increase our speed to match the frequency we could actually surf a trough and minimize slewing. Alas, great boat that she was, she didn't have quite enough "bazoom" to accomplish this.

I had something similar occur a couple of weeks ago as I was approaching the Carquinez Bridge. The wind was kicking up and the ebb tide was ending but the rollers were still present.

This video doesn't really capture it very well, but the 2-3 footers were rolling past me and causing large, but predictable heading changes as the bow would rise and fall. Once I bumped the revs from 1800-2000, the boat more evenly matched the roller speed and the oscillations settled down.

I was just playing with it and trying to find the sweet spot while the conditions were present. As soon as I passed under the bridge, it all flattened out again and the flood began to push me along.

What type steering system? I recommend getting it so that 4 turns full swing is max. Good luck!