Anchoring Stern-to in a Storm

[Wand]

Originally Posted by mrohr

If your boat shears about at anchor ,get some of the junk off the decks ,esp. forward and start thinking about windage.

And underwater profile... Maybe time to unbolt the long stick with the bulb on the bottom and glue on a nice long keel?

[speakeasy]

Originally Posted by Dockhead

Have we come to any conclusions about this? I recall it was much discussed over the years.

The problem with lying to an anchor in a really bad storm is that the center of aerodynamic pressure of your boat with the sails down is ahead of the boats center of gravity as well as the boat's keel. That means that wind pressure tends to make the boat's head fall off -- tends to blow the bow off. It means that being anchored bow-to is inherently unstable in a strong wind.

That's the same principle which explains why it can be hard to get your boat's head through the wind when it's really blowing. And why backing up into a strong wind is the best way to maneuvre in close quarters and strong wind. Your boat will back into a strong wind with stability, because the wind will not blow the stern around like it does the bow. That's because the center of pressure is behind your keel, when you're backing up, so the effect of wind when backing upwind is just to keep you on course, not blow you off.

Apparently that's the same principle that makes a boat yaw at anchor in a strong wind. This yawing can break your anchor rode or snubbers or bridle in a really bad storm. There are many accounts of boats anchored in hurricanes yawing wildly, and being knocked on their beam ends at the end of every yaw, putting huge stresses on the ground tackle.

So someone recommended anchoring stern-to in such conditions, claiming that the boat will lie stably like that.

Has anyone actually tried this out in anger? Any thoughts?

A few thoughts. What you've postulated makes sense of a recent attempt to leave dock with my new boat. Had wind 30' off port bow at 15 kts. I figured it was perfect and would aid my backing out to starboard and leaving forward in a port turn. Not so. A hodgepodge of line handlers notwithstanding, the bow blew off to starboard pinning the boat aft port to the dock and nothing I tried altered the situtation. Fact was the stern kept cocking into the wind as the bow blew off.

If true, that backing into the wind is a stable event with a double-ender, that will add a big arrow to my quiver. We shall see at next opportunity to practice, a month at least hence, probably two with xmas travel and re-rigging on plan.

If that does pan, the ways indicated above, then anchoring stern to the wind might make good sense for my new old boat, except for driving rain issue which is smaller with my boat's hardtop. She looks to be almost finer in the butt than the bow. The rudder tactic then becomes crucial. How does water move into/under the boat with a pointy stern in a storm? Side loads? Lock amidships? Lock to one side, based on what?

Interesting discussion, thanks.

[boatman61]

Speakeasy.... lashed central... the idea is to decrease possible loads... to my simple mind lashing the tiller to port or stbd is creating a load that will push your stern in the opposite direction to the lock.... but hell... what do I know
When I anchor bow on which for me is the only way.... I lash the tiller/wheel hard over to one side... it does not stop the yawing when the wind picks up but does minimise the amount I swing one way... also when it gets over 25kts I drop the topping lift so the boom is draped down to favour the lock of the rudder and is helping steady the boat.

[speakeasy]

Thanks, Boatman61, amidships was my instinct. Topping lift, eh. How does that reinforce the rudder. tanks.

[boatman61]

Originally Posted by speakeasy

Thanks, Boatman61, amidships was my instinct. Topping lift, eh. How does that reinforce the rudder. tanks.

I'm talking about anchoring from the bow.... tiller lashed to port... normally this would turn you to stbd.. yes..??
Ok so if you drop your boom with its sail and boom cover so's it rests on the cabin top/sidedeck on the port side its going to exert pressure to push you to back.. it cuts the yaw by half and reduces windage to boot... mind this is small boat tactics..
tiller to port.. boom to port... you don't take as many waves on the bow... more on the 1/8th
You 'Big Boys'.... dunno... experiment.. but it works for me

[Jimbo2010]

With hurricane Irene on its way I'm seriously considering doing this.

Last year in good 50-60knot blow through my harbor I noticed that a lot of gear was thrown about down below.

Which leads me to believe it was laying over.

I'm in a protected harbor on a 400# with good chain, my boat a Ben36.7 has an open stern which will dump water quick.

The stern cleats are as big as the bow.



???????

[clockwork orange]

More than thirty years ago i used to see the 40ft cat Sundancer moored stern first in the mooring field off Birkinhead point in New Zealand in all kinds of weather, it had transom hung rudders but small transoms and a lot of bridgedeck clearance.
Steve.

[rtbates]

I do it all the time...Granted, not in winds above 40kts, yet... IT WORKS!!!

[Matt Johnson]

What about all the engine vents, exhaust, cockpit drains and other things that are now pointing into the wind and waves. It seems that you would get a pretty good back flow into everything including the exhaust and engine.

[zeehag]

during my tenure on a mooring ball, i was always bow to and received no ingress os water other than from the sky.