At anchor

[a64pilot]

If one is rolling significantly more than others,
as other people have already said the waves at at that boats natural resonance frequency.

Think of pushing a kid on a swing, you don't push once and get them to the highest swing, no you push a little every time the kid hits the top of the swing and just as they start down, every time you push a little, the kid swings higher.

Waves can do exactly the same thing, if they hit each time just as the boat is at the max roll, just little waves can really get a boat going. Used to get into it all the time fishing in a power boat, fish on, boat to neutral and start fighting the fish, boat turns beam on to the waves and buddy let me tell you if they are just right even little waves can get a big ole Sportfisher rolling so bad that it can throw someone out of a flybridge or Tuna tower, but they have to be at just the right period.

[barnakiel]

You want a cat.

If you are in a mono, pray for a beamy flat hull.

If you are in a long narrow deep keel mono, she will roll your guts both in port and at sea.

Size helps too. All other things equal, bigger boats roll less and slower.

b.

[Ocean Girl]

We have a big beautiful Kadey Krogen (45 +) to out port and a big beautiful Pan Oceanic (43) off our stern. The oceanic definitely has a nicer motion.

I think when most of us talk about comfort at anchor, we are not saying no movement, that's land. As sensitive as I am to movement, right now I feel like rain dog is still, but I look up at the oil lamp, the hanging nets, and they are all gently swaying. She has a nice sweet motion :-). When it's so rough you need sea cloths, well, that's an uncomfortable anchorage.

[barnakiel]

Some otherwise lovely cruising boats roll at anchor to an extent that always puzzles me. Like Amels Super Maramu. They are BIG boats, and yet. Some combo of hull shape and other factors and we do not look too bad in our little 26 ft rock'n roll boat.

b.

[barnakiel]

BTW sugar scoop becomes less and less a feature these days.

b.

[Don C L]

Originally Posted by unclemack

Hadn't thought about it before reading this thread but is it possible that, when there are a number of nearby boats on pontoons - not anchored obviously - movement of boats might be affected by waves reflecting from others nearby as well as from fixed structures?
Like reflected waves from headlands, moles etc.?

If so presumably some would have their movement amplified and others have it suppressed - some boats causing others to reach their resonant period of roll and others prevented from achieving resonance.

Yes, I have noticed where I am that waves reflecting off of nearby cliff faces will affect how I roll, and yes I always anchor with my flopper-stoppers out to dampen the resonant... well, in flying they call it PIO, pilot induced oscillation, but it must have some other name for a boat rolling...

[boatman61]

Guys... he sounds like he's tied up to a slip/pontoon... anchor tactics don't work there

[quote] I'm sorry I cannot report the type vessel we were on but It/she was just laying so comfortable in the marina, while the other boats on ether side of us were thrashing about. RIGHT NEXT TO US![quote]

[donradcliffe]

The only rolly marina I know of in Langkawi is the yacht club in Kuah, where you get waked by the passing ferries. Some docks get hit a lot harder than others.

[Jubilee39]

Maybe it has to do with perception also, if you just came back from sailing for a couple 8f weeks the motion is comfortable and somewhat unnoticaable but you can see other boats moving. BTW Kay Sera was docked next to me in Langkawi and except for the duckboat caused wake never noticed uncomfortable movement

[Adrenaline]

I can't believe no one said having two hulls helps

[boatman61]

Originally Posted by Adrenaline

I can't believe no one said having two hulls helps

See post #14

[s/v Jedi]

The rigging is a big factor for comfort at anchor. A ketch or schooner is much more comfortable than a sloop which will be sailing back and forth behind the anchor.

[boatman61]

Jedi.. your mizzen the point..

[unclemack]

Originally Posted by s/v Jedi

The rigging is a big factor for comfort at anchor. A ketch or schooner is much more comfortable than a sloop which will be sailing back and forth behind the anchor.

Hi, roller genoa, roller staysail solent rigged and retro-fit in-mast furling means I've lots of windage forward.

Storm jib hanked on one of my backstays & sheeted forward stops it sheering about and helps reduce mast pumping too.

[twoblocktom]

Thanks everyone! Sorry I can't remember more about the trip I mentioned. When I noticed how different the motion was on boats so close together, I wondered why!