Best hull design for comfort at anchor?

[Don C L]

Flopper stoppers! I have a rolly boat but with flopper stoppers hung out on both sides she just sits there for the most part. Otherwise I still think a cat will be the best option. I've seen heavy deep drafted boats roll quite a bit when the wave period matches the hull's... what's it called? Harmonic frequency? And beam doesn't necessarily help either, though my beamier friends seem to roll less than I do.

[Johan Leopard51]

First point is “at anchor” not on a good mooring buoy. That already makes quite a difference. Intrinsically for me, a buoy has far less run-around from its enormous capacity to a short distance relative to depth. I would in winds rather be on a good buoy on (relative to depth) short bridle than 150 feet of anchor onto same bridle.

Tide is the other bugger. Around islands and atolls you very easily get yourself side-on wind because of strong current. I can’t say whether tide affects cat more than mono but possibly yes(?). Most times we did drag anchor was that : we’re broadside to wind because of current.

In our case (51 powercat) we have relatively low wind profile and on anchor with longish bridle we are very comfortable unless that thing with current. But I suspect same applies to a long heavy mono hull. A 65 foot monohull with mast and boom scooping wind with very strong current will def drag its anchor before a cat on proper bridle. That is just math on beam vs length.

[smj]

Originally Posted by caribbeancruise

I was initially thinking our solar arch and dinghy would provide enough windage aft, but in hindsight, that is pretty negligible in comparison to the bow and roller furling. Dragging a second anchor or small chute from the bow also sounds like an interesting idea! Live and learn, wish I had asked the question before spending a season in the Bahamas! This year will now be much more comfortable no matter what boat we end up on thanks to all of these great suggestions.

We're leaning towards a "newish" cat 2008-2017 - each one seems to have it's own set of documented issues. Like arsenelupiga mentioned, we'll look at the bulkheads on the newer 39, 40 and 42 Lagoons carefully (the 450 is beyond our budget). Would love to find a newer Garcia, Ovni, Besteaver or the like, but they're also beyond our current budget. That'll be a topic for another thread .

For your catamaran budget look beyond the Lagoon/Leopard/FP mindset. Lots of great well built cats in that price range.

[caribbeancruise]

Originally Posted by smj

For your catamaran budget look beyond the Lagoon/Leopard/FP mindset. Lots of great well built cats in that price range.

Agreed, but a lot of them tend to be older. The few sub 2010's that we've seen down here have had moisture issues—anything from the "typical" high readings around hatches and hardware to questionable bulkheads. Definitely keeping an open mind and searching boats.com among other sources daily for something on the East Coast of the U.S. We've considered expanding our search and looked into shipping with Sevenstar, if the right boat came along, we might just go that route (taxes and insurance seem to complicate those options as well).

[Johan Leopard51]

Hopefully in next 5y somebody comes up with the ideal vessel:

Cat for living space and comfort at anchor.
Sail with high boom so as to have a shaded flybridge but the excitement of sail, which I do miss on powercat.

= can sail when there is wind, can motor when there ain’t no wind at decent fuel consumption. So twin say 150Hp motors.

I really have no desire to do 25 knots on diesel - unless I’m running for survival, which with planning would never be the case.

[GordMay]

Ship motions are defined by the six degrees of freedom that a boat can experience: heave, pitch, roll, surge, sway, and yaw.
What Chotu is calling “rocking” is formally described as “pitch”. This is characterized by the rising and falling of the bow, and stern, in much the same way as a teeter-totter moves up and down.
These six freedoms are divided into two categories: three translational [linear] degrees [heaveing, surging, & swaying], and three rotational degrees [pitching, rolling, & & yawing].

See “An Introduction to Seakeeping” ~ US Naval Academy
➥ https://www.usna.edu/NAOE/_files/doc...5_Chapter1.pdf

[Chotu]

Originally Posted by GordMay

Ship motions are defined by the six degrees of freedom that a boat can experience: heave, pitch, roll, surge, sway, and yaw.
What Chotu is calling “rocking” is formally described as “pitch”. This is characterized by the rising and falling of the bow, and stern, in much the same way as a teeter-totter moves up and down.
These six freedoms are divided into two categories: three translational [linear] degrees [heaveing, surging, & swaying], and three rotational degrees [pitching, rolling, & & yawing].

See “An Introduction to Seakeeping” ~ US Naval Academy
➥ https://www.usna.edu/NAOE/_files/doc...5_Chapter1.pdf

exactly. I had it as pitch in my post at first, but then I changed it. Too many people call it hobby horsing commonly so I didn’t want to take away from the common usage

[mvweebles]

Sailing (yaw) at anchor is a much different issue than hobby-horsing (pitch).

You'd think being tethered at the bow that it would point-up into the wind like a windvane on a barn. Except there are hydrodynamic forces that will orient the hull perpendicular to the seas (drift in open water with a breeze and you'll see). By tethering the boat, a cage match is created - wind wants the bow pointed directly into the wind, water wants it perpendicular. They go back and forth ---- literally. A riding sail may attenuate the effect but can only do so much. Re-orienting the bridle with one leg to midship may also bias the conflict enough to reduce yawing (similarly, widening the bridle as possible on catamarans certainly helps).

I think its hard to beat the at-anchor comfort of a catamaran. Less prone to both hobby horsing (pitch to adopt GordMay's technical citation) and sailing at anchor (yaw). My displacement trawler has flopper stoppers with 12-foot outrigger poles on both sides which creates a 28-foot wingspan and all but eliminates rolling, but still my friends 52-foot powercat is much better.

[hpeer]

In our experience most discomfort cones from rolling. We have a very heavy steel boat with a long cut away full keel. We frequently see others rolling much worse than us and have had this conversation before.

We do have some hobby horsing but it has inly been bad in one very unusual circumstance, St Pierre, we had a wind against current situation blowing waves up our stern. Quite impressive pitching. I put out a weighted drogue off the stern which took the bite out of it.

I believe the heavy displacement along with the big keel damps the roll significantly. We have seen others in larger modern boats wuit an anchorage due to rolling while we were quite happy. And the Wife is prone to motion sickness so its not because we are tough.

Another factor may be an interior layout that keeps you in the center of the motion where it is felt less. The end of a wide bot would be bad. Mid ships is generally calmer.


I have deployed a steadying sail at times. Helps a bit.

Also long skinny snubber.

[rslifkin]

Originally Posted by Chotu

exactly. I had it as pitch in my post at first, but then I changed it. Too many people call it hobby horsing commonly so I didn’t want to take away from the common usage

In my mind the phrase "hobby horsing" makes me think of a specific kind of unpleasant, excessive, continuous pitching motion. Particularly the kind you can get from a hull with lots of rocker and narrow ends.

[Chotu]

Originally Posted by rslifkin

In my mind the phrase "hobby horsing" makes me think of a specific kind of unpleasant, excessive, continuous pitching motion. Particularly the kind you can get from a hull with lots of rocker and narrow ends.

correct. Exactly. That’s pitch.

And if you live at anchor like I do, It becomes part of the equation.

When winds are above 35 knots or so with some fetch, it’s a real part of the comfort.

I didn’t go into roll, because obviously Catamaran stops all of that. It didn’t really need discussing

[rslifkin]

Originally Posted by Chotu

correct. Exactly. That’s pitch.

And if you live at anchor like I do, It becomes part of the equation.

When winds are above 35 knots or so with some fetch, it’s a real part of the comfort.

I didn’t go into roll, because obviously Catamaran stops all of that. It didn’t really need discussing

Agreed. But a boat can pitch without it being an obnoxious hobby horsing motion.

[massnspace]

One of the boats we own is a small, trailerable sailboat. Water ballast. So it is tender, both when sailing and at anchor.

We invested in 4 Davis Rocker Stoppers. $60. I rig them off the swung-out boom when at anchor. Night and day difference, really an amazing stability. Just make sure to put a heavy (minimum 10 lb.) weight at the bottom. A lot of people forget this step and they do NOT work at all without a big weight. And this setup does not dampen hobby horsing, only side to side roll, but it works brilliantly at that.

Our next test, on our much bigger sailboat, is going to be as follows: Buy about 20-25 of these. Total cost $300-$400. Rig them in groups of about 4, on lines, with lead diving belt weights, all ready to go, line attached to gunwale, in 5 gallon buckets permantly attached to stanchions. (They are designed to fit into a standard 5-gallon bucket). Several on each side and one on bow and one on stern for sure.

When we anchor, just walk around and throw them in, one at a time. Should take about 60 seconds.

I am guessing 25 of these will make a huge difference in pitch and roll motion. But I guess we’ll see.

Of course the white buckets will look ugly, and clog up the side decks a bit, but we never go to marinas, always anchor out, so I don’t really care how we look. And I will trade off losing a bit of deck walkway space for the 14 hours of greatly increased stability at anchor each evening, night and morning…

[AiniA]

Never thought about comfort at anchor since we always had it with our Bristol 45.5. Heavy displacement and perhaps the secret sauce, very full bilge shape which was very stabilizing I think. Same design butt more money, Little Harbors.

[Don C L]

I've used those Davis Rocker Stoppers, and they work fine, but they do require the weight and they don't stow easily in my small boat. So I switched over metal frame designs similar to the attached article with spinakker poles as outriggers. The metal ones are easier to stow and don't require a weight.

https://www.cruisingworld.com/how/re...oppers/#page-4