Trawler Rocking, Rolling and Stability

[Hippocampus]

stuck waiting as I download chart updates today. Very windy and t storms expected shortly so,like you wasting time.
I’ve spent quite some time with Webb Chiles. He still has and sails his Moore 24 with which he circumnavigated multiple times. Even now he has no fixed MFD, no watermaker, only a tiller pilot, no frig nor freezer and best I could see no pressure water. He has four truly ancient small flexible solar panels totally crazed. He’s in the process of replacing those.
BTW believe no crash pump, no raft, no ditch bag, no installed satellite communications, no Starlink.
He still sails around the Hilton Head area at 80+ years of age.

 

[Mako]

I used to also be a big believer in "minimalism" but I seem to have passed a certain age and now I want a certain degree of comfort. Otherwise what's the point of traveling and exploring if you can't enjoy yourself? However, I still don't like "complicated" so I'm trying to find a happy middle-ground when it comes to building/equipping a boat. Maybe the correct word would be simplified.

 

[KnotYet]

stuck waiting as I download chart updates today. Very windy and t storms expected shortly so,like you wasting time.
I’ve spent quite some time with Webb Chiles. He still has and sails his Moore 24 with which he circumnavigated multiple times. Even now he has no fixed MFD, no watermaker, only a tiller pilot, no frig nor freezer and best I could see no pressure water. He has four truly ancient small flexible solar panels totally crazed. He’s in the process of replacing those.
BTW believe no crash pump, no raft, no ditch bag, no installed satellite communications, no Starlink.
He still sails around the Hilton Head area at 80+ years of age.

Tiller pilot?
Luxury!

 

[Mambo42]

I used to also be a big believer in "minimalism" but I seem to have passed a certain age and now I want a certain degree of comfort. Otherwise what's the point of traveling and exploring if you can't enjoy yourself? However, I still don't like "complicated" so I'm trying to find a happy middle-ground when it comes to building/equipping a boat. Maybe the correct word would be simplified.

I never liked minimalism and never liked camping. We like to travel with all the creature comforts that make life 'sustainable' in other words we like all the comfort we can get.

 

[Mambo42]

Thanks for that post Mambo but think the devil in in the details. I have found although the SeaKeeper is totally amazing in decreasing roll it has little if any effect on pitch. The hydraulic arms will force the vacuum contained gyro to move in the AP direction(forward and aft) but has no degree of motion in the transverse plane ( athwart ship). In short it has minimal if any effect on pitch. Best I can tell the gimbals allow it to swivel only in one plane.

Ah ok, I understand it is only 1 axis stabilized and then indeed it won't be able to stabilize in pitch. Wonder though what made them decide not to go for multi axes, would have made more sense. Cannot be that much more expensive.

The fact it can’t pivot in the athwart ship plane is how it resists roll.
We haven’t spun it up in big seas but have in chop up to ~3’ even if on the same course for hours and hours it works fine and keeps us level. Haven’t spun it up when there’s already a list so don’t know if it would keep us on that list but think it might. So far when I hit the button to get it working after spin up if there’s chop head directly in to it so we’re pretty level. I say it again we are now coastal. Spin it up in a slip or at anchor. Have had it up to 3-4’ short period chop as well as swells and it’s amazing. Can’t say anything more from personal experience.
What we really need is a good engineering mind more familiar with the device or contributions from others who have gyros. My understanding is that if you have a sustained list before going off or while underway there’s a possibility in will try to preserve that list. Given being beam on is lousy on power or sail in the past when on sail we would zigzag to improve the ride quality. Still do that to the extent possible. Have yet to have the SeaKeeper induce a list.
In short I don’t think it ever knows what’s level.

I guess that, as long as you start it up on time, you should be fine. Best practice with the gyro is to spin it up before every trip, so that you are fully stabilized before you get off the dock or anchorage. At that moment the whole system will probably perform pretty good, the principle after all makes a lot of sense.

 

[Hippocampus]

Great thing about being coastal is you know before leaving what sea states you might face. Even with the best forecasting and weather routers you don’t beyond 3-5 days at best. Gribs aren’t granular enough. Have been in atrocious weather when they show one vane or blue. Have been told a system is moving slowly when it’s trucking along. Doesn’t matter which model. Also white squalls, micro bursts and just plain bad stuff can catch you unaware.

You won’t have 45 minutes to spin up a SeaKeeper. Although none of the devices (fins, fish, gyro, Magnus) improve stability even if they only help to allow you to move around and function it’s worth the money in my view. But don’t think I’d put a gyro on a blue water boat. A ship is a different story but not a boat.

Both NASA and the Navy have done extensive research on motion sickness. Turns out there’s a multiplicity to motion in two axis and again with three. It’s not additive. That’s why some people are sensitive to corkscrewing but can tolerate roll. Also with pitch you can use a neck, ankle or knee/hip strategy to keep your utricle and semicircular canals dormant more easily than with sway. To date no one has puked on my boat. Getting rid of roll is a big deal.

 

[Mako]

@Hippo, would like to know what your thoughts were about other gyros, in particular the QuickItaly model

 

[Hippocampus]

It’s much lighter and not in a vacuum. Being lighter less force generated. Not in a vacuum so more resistance to spinning so more energy required to get up to decent rpms and stay there. Upside of no vacuum is can do servicing while on the boat with brief downtime. No free lunch for anything on a boat. Probably a good choice for a LDL and note Artnautica has a Quick as an option. But personally for a boat like that could see using a Quick but also have Humphrees or Magnus master (if frequently in skinny water).
Would also like it in a center console deep V that does frequent bottom fishing. Less weight to get on plane but stable platform for fishing.

 

[Jpmelliott]

We installed our Waveless STAB 20 electric fin system 3 weeks ago. 17 hours underway and 174 hours in anchor mode (zero speed). Very pleased. Power consumption is nominal ~100 Watts underway and 135W average at zero speed. We have 21kWh of LiFePO4 so, we can go days on end without recharging.

We’ve experienced a couple outings with 30knt sustained and 45knt gusts. 5 ft trailing seas used to be absolute punishment on our 2010 48’ Navigator (especially with her tall bridge hardtop). No longer. It is absolutely surreal how flat she rides.

The 180 degree fin rotation at anchor stops her from walking up on the rode. A very elegant solution in our early assessment.