Fin keels and low water

[Vid]

I’m still trying to decide whether my next boat should be a gin or twin keel. What happens to a fin keel yacht at low water in a typical east coast anchorage (eg Yokesfleet creek) if the draft is 1.5m but there is, say, 1.3m or 1m depth? Would it typically just settle into the mud but stay upright, or would it start leaning over at some point? Example boat is a Sadler 29.

 

[PaulRainbow]

If the mud is soft it will settle into the mud, if not, it'll fall over.

Places such as Tollesbury, where most of the moorings dry out, have boats with 1.5m draft, or more, that settle into the mud at low water, when there is no water at all. You'd want to be confident of the bottom before doing it though.

 

[pvb]

Bilge keels can suffer stress damage from repeatedly drying out in mud.

 

[Plum]

I’m still trying to decide whether my next boat should be a gin or twin keel. What happens to a fin keel yacht at low water in a typical east coast anchorage (eg Yokesfleet creek) if the draft is 1.5m but there is, say, 1.3m or 1m depth? Would it typically just settle into the mud but stay upright, or would it start leaning over at some point? Example boat is a Sadler 29.

It comes down to local knowledge. Some of the East Coast mud is softer than others and a few areas of the East Coast are sand and shingle. You can't generalise. Once you know a particular anchorage or creak you will then know what depth you can successfully anchor in. You will certainly not be alone on the East Coast with a single keel!

Www.solocoastalsailing.co.uk

 

[Vid]

It comes down to local knowledge. Some of the East Coast mud is softer than others and a few areas of the East Coast are sand and shingle. You can't generalise. Once you know a particular anchorage or creak you will then know what depth you can successfully anchor in. You will certainly not be alone on the East Coast with a single keel!

Www.solocoastalsailing.co.uk

I understand that, the question is more about how a boat would settle

 

[ex-Gladys]

I've anchored many times in the Yokesfleet with a 1.5m fin, and you don't even know she's taken the mud... Lovely...

 

[johnalison]

One concern is that the boat might dry out and heel towards deep water and fill up. You would have to be pretty careless and on a firm bottom for this to happen. We managed both on one occasion in our then Mystere in the Roach once, but no water came aboard.

Generally, some or most of the fin sinking into mud is no problem. Once, at the top of Hamford Water where the channel is narrow, we settled on the sloping side and our slightly bulbous keel steered itself down into the deepest water as the level dropped.

 

[Plum]

I understand that, the question is more about how a boat would settle

As others have indicated, you will certainly settle upright if the mud is soft and deep enough. Don't forget to close the seacocks beforehand as in the really soft stuff it can get forced in.

 

[xyachtdave]

I understand that, the question is more about how a boat would settle

Hey Vid!

I've run aground in the Medway broaching under spinnaker and had the keel all the way in. No bump, no bang, just a slow decrease in speed. The boat sat up bolt upright, we were more worried it wouldn't come out than the boat falling over!

I've anchored a bit too casually by Kingsnorth and woke up with the boat at 45 degrees, 1.5m of water with 1.9m of draft.

There's loads of mud so generally not a problem but occasionally there'll be something hard on the bottom for your fin keel.

 

[Concerto]

One concern is that the boat might dry out and heel towards deep water and fill up. You would have to be pretty careless and on a firm bottom for this to happen.

In over 50 years of sailing I have only known that nearly happen once to a Twister who was in a narrow muddy creek as he ran aground close to high water. His keel was too broad to sink in the mud and he misjudged where the depper water was and inclined the boat the wrong way. Luckily he called for support and some large racing marks were brought in to help him float rather than sink when the tide returned.

Any fin keel boat will rarely ground if you are careful where you anchor. I have sunk fin keels into soft mud and stayed upright. The OP should try and check where he plans to moor for depth and the bottom structure. Personally I prefer never to ground in mud as you always get a residue left on the keel and this stops the antifouling from working so aids weed growth if not permanently sinking into mud every tide.

 

[STOL71]

I would have thought that any boat will fall on its side if the ground is hard enough and not sufficient water to keep it afloat.
The Achilles’s would be the rudder, especially if it is just a spade without the protection of a skeg or keel.

 

[Dan Tribe]

As an East Coaster with a 1.8m draught, I'm no stranger to sticking my keel in the mud. Normally it sinks straight in, occasionally we heel a bit.
I have only ever seen one boat fill and sink, that was an old 8 metre design, very deep and narrow. It leaned away from the bank , the cockpit was not self draining so it never stood up on the returning tide. It is a worry but very rarely happens.
I also used to worry that my old Stella would balance on the flat bottom of the keel and NOT lean over until the water had gone. Never happened.
Strange how many things there are to worry about in the small hours.
BTW do we choose a boat because it sails well or because it parks well?

 

[Tomahawk]

Sals..

 

[Concerto]

I feel a boat should be in water, not resting on its keel. I anchor to maintain this.

 

[Dan Tribe]

I feel a boat should be in water, not resting on its keel. I anchor to maintain this.

That is also my ambition, but sometimes I fall short.

 

[TLouth7]

Any post 1979 designed yacht (not keelboat) shouldn't downflood when heeled to 90 degrees so shouldn't be at risk of flooding as the tide comes in.

My fin keeler takes the ground in soft mud with every tide and generally gets maybe 15cm above her lines before starting to heel.

 

[johnalison]

Any post 1979 designed yacht (not keelboat) shouldn't downflood when heeled to 90 degrees so shouldn't be at risk of flooding as the tide comes in.

My fin keeler takes the ground in soft mud with every tide and generally gets maybe 15cm above her lines before starting to heel.

I think that the JOG specified that a boat should be immune to flooding at 90 degrees a little earlier. I think that my 1973 Mystere would have been built with that in mind, but earlier boats such as Westerlys were probably equally safe.

 

[Concerto]

To heel to 90 degrees means the keel must be resting at a higher point than the hull. This image has been rotated to show what I mean. The bank as drawn in would have to fall away pretty steeply to get to horizontal.

 

[AntarcticPilot]

Any post 1979 designed yacht (not keelboat) shouldn't downflood when heeled to 90 degrees so shouldn't be at risk of flooding as the tide comes in.

My fin keeler takes the ground in soft mud with every tide and generally gets maybe 15cm above her lines before starting to heel.

But if you ground on the edge of a channel and end up leaning downslope, you could conceivably end up heeled more than 90 degrees. It has happened on the Humber and the Clyde, with commercial vessels being lost. Less likely on the East Coast, where the channels are less likely to be steep sided, but...

My boat is 1989 vintage, and although I think she'd come up from heeling at 90 degrees, I don't fancy testing it. At best, she'd be a dangerous environment for the crew heeled to more that 45 degrees.

 

[johnalison]

There is something uniquely awful about the experience of being in a boat that has grounded and heeling well over. The same degree of heel while under way is no problem but the unyielding nature of the unfamiliar and sloping environment is quite disorientating.