Bulb Keels Mooring in Mud

[grahamwhittle]

I am looking for a sailing boat 30 to 36 feet loa to moor in Granton Harbour, Edinburgh.

There are many fin keeled yachts moored there which settle into the mud at low tide. Obviously a deep 2m+ high performance keel is not suitable. I have talked my self out of a bilge keel or a swing keel. I feel a draft under 1.7m is needed because of the tide and the mud, and that is the maximum draft of virtually all the boats moored there.

The sort of yacht I have in mind is a Bavaria, Jeanneau, Beneteau or Hanse type of production yacht, but I find that those that meet the draft requirements have bulb keels. Do any members of the Forum have experience, of bulb keels settling in mud?

None of the boats moored in the harbour have bulb keels as far as I can discern, but I believe that this is because they were built before the bulb keel production yacht era. I have made inquiries at the yacht club but even the most experienced salts were unable to advise.

 

[Minerva]

If you keep a fin keel boat in Granton; your cruising options are either Burntisland or Port Edgar (both pretty crap options) - other than that your are only going to do day sails of a couple of hours.

If it were me, I'd either buy a lifting keel boat (as you ruled out bilge Keels) to open up the option to visit other harbours in the Forth or just buy a beautiful keelboat like a Dragon / Ettchels / Soling.

Top answer your actual question, I cannot see a bulb working well in Granton Mud, not can I imagine performance being sparkling when your trying to sail with a big hunk of mud sat on the top of the bulb.

 

[grahamwhittle]

Thank you for your reply. I was very interested in the Beneteau 311 with a swing keel until I read some of the posts about then on this Forum. The chore of winding, the slapping sound, muddy water in the boat, access for bottom cleaning.

 

[dunedin]

….. or do what most people end up,doing with a boat like that, moor it on the Clyde rather than the Forth. Worth the extra drive for better sailing grounds and no depth issues

 

[wallacebob]

Most harbours on the Forth end up with the size/type of boat the works for that location. I started at Fisherrow, “you don’t want a lift keel” was the advice, gets stuck! If you don’t want to use Port Edgar, then it may limit your boat choices. Lots of Older twin keel Hunters or bilge Westerly are around for a reason.

 

[TLouth7]

My boat is in Granton and with a 33' LOA and ~1.5m draft it's one of the biggest yachts. 36' would look huge here. Many of us in the deeper water dry pretty much upright which only happens because the bottom foot or so of the keel is in the mud. However the H Boats have long keels and don't dig in so lie on their sides perfectly happily; whether a larger cruiser would tolerate the same conditions I don't know.

PS are you sure you don't want a nice J24? We have one in the FCYC yard going for a song...

 

[johnalison]

I think the only keel type to be a potential problem would be a wing keel, but even then it seems unlikely. I have a blob rather than a bulb and it has never concerned me.

 

[magicol]

I’d be reluctant to keep a boat with a bulb keel at Granton. There is less shelter in the deeper parts of the harbour and I wonder how a rising tide works on a bulb buried in mud. I‘ve lived in Edinburgh and crewed out of Granton but never kept a boat there. My 34 foot Hanse has a bulb keel and as Dunedin says, it is better suited to the Clyde and West Coast where for me, the greater opportunities to sail outweigh the longer commute.

 

[grahamwhittle]

My boat is in Granton and with a 33' LOA and ~1.5m draft it's one of the biggest yachts. 36' would look huge here. Many of us in the deeper water dry pretty much upright which only happens because the bottom foot or so of the keel is in the mud. However the H Boats have long keels and don't dig in so lie on their sides perfectly happily; whether a larger cruiser would tolerate the same conditions I don't know.

PS are you sure you don't want a nice J24? We have one in the FCYC yard going for a song...

Thank you for the note about the J24, it would be a great day sailer, which is my interest.

I’d be reluctant to keep a boat with a bulb keel at Granton. There is less shelter in the deeper parts of the harbour and I wonder how a rising tide works on a bulb buried in mud. I‘ve lived in Edinburgh and crewed out of Granton but never kept a boat there. My 34 foot Hanse has a bulb keel and as Dunedin says, it is better suited to the Clyde and West Coast where for me, the greater opportunities to sail outweigh the longer commute.

Thank you, I wonder too, hence my post. The Clyde is a wonderful sailing area, I have have some experience there. But living only a short walk from Granton harbour, I hope to enjoy some day sailing out of there for a bit of fun.

 

[grahamwhittle]

I think the only keel type to be a potential problem would be a wing keel, but even then it seems unlikely. I have a blob rather than a bulb and it has never concerned me.

I see you are in Essex, do you moor your “blob keel” in mud there?

 

[oldmanofthehills]

Having had a lifting bulb keel, I can assure folks that in softish mud it soon digs a nice slurry pit for itself probably within a few days (whether raised or lowered in my case) and soon pulls free of the mud in the rising tide. Compared with the 6 ton or so of displacement lifted by the hull the downward drag of any keel is trivial. I suppose a wing keel could catch on some unmovable debris but I have never heard of it. Any mud resting on the bulb will soon self discard once moving.

Perhaps in hard mud its different but fin and long keels with sit at funny angle there also if ground too hard, then bilge is your man

 

[bitbaltic]

Compared with the 6 ton or so of displacement lifted by the hull the downward drag of any keel is trivial.

Maybe not so trivial for the bolts holding it on. Pulling a sucking keel out of mud seems a good way to fatigue keel bolts to me.

 

[John_Silver]

I see you are in Essex, do you moor your “blob keel” in mud there?

A couple of years back I put Stargazer (Rassy 310, 1.8m draft, bulbed fin) aground coming out of Pyefleet Creek. Which is notorious for its oozy East Coast mud. It was just after high water. So the wait to refloat was long and, with a gale building, anxious. But (as per the description / pix in the link) she came off unscathed. It is not an experiment which I have cared to repeat. So I cannot attest to the effects of frequent repetition!

 

[penfold]

Maybe not so trivial for the bolts holding it on. Pulling a sucking keel out of mud seems a good way to fatigue keel bolts to me.

If that was true they would fatigue and fail just by a boat being launched and recovered; keel bolt fastenings are invariably grossly overengineered.

 

[johnalison]

I see you are in Essex, do you moor your “blob keel” in mud there?

Not deliberately but the bottom goes into mud at low water sometimes by maybe 6".

 

[Birdseye]

I am looking for a sailing boat 30 to 36 feet loa to moor in Granton Harbour, Edinburgh.

There are many fin keeled yachts moored there which settle into the mud at low tide. Obviously a deep 2m+ high performance keel is not suitable. I have talked my self out of a bilge keel or a swing keel. I feel a draft under 1.7m is needed because of the tide and the mud, and that is the maximum draft of virtually all the boats moored there.

The sort of yacht I have in mind is a Bavaria, Jeanneau, Beneteau or Hanse type of production yacht, but I find that those that meet the draft requirements have bulb keels. Do any members of the Forum have experience, of bulb keels settling in mud?

None of the boats moored in the harbour have bulb keels as far as I can discern, but I believe that this is because they were built before the bulb keel production yacht era. I have made inquiries at the yacht club but even the most experienced salts were unable to advise.

what problem are you thinking of? A boat in your size range will typically weigh 5 to 7 tonnes so the buoyancy lifting the keel buried in mud will of course be 5 to 7 tonnes..

 

[vyv_cox]

Maybe not so trivial for the bolts holding it on. Pulling a sucking keel out of mud seems a good way to fatigue keel bolts to me.

Fatigue is caused by cyclic stress. Pulling a keel out of mud is a tensile force. No similarity between the two.

Keel bolts would typically be 8 - 10 in number, often 24 mm diameter. In old numbers their strength would be 30 ton/ sq.in, so each bolt will sustain around 20 tons. Well over what could be generated by floating out of mud.

 

[grahamwhittle]

Thank you for your brilliant answers to my question. I am scheduled to view a Moody 31 of 1989 vintage in Greenock on Thursday. No bulb keel. It would suit the task, but I think will not have the zing of a 2009 Han/Bav/Jea/Ben light displacement “production”yacht, most of those with suitable drafts have bulb or wing keels. After reading your replies I am seriously contemplating give the younger girls a chance.

 

[dunedin]

Thank you for your brilliant answers to my question. I am scheduled to view a Moody 31 of 1989 vintage in Greenock on Thursday. No bulb keel. It would suit the task, but I think will not have the zing of a 2009 Han/Bav/Jea/Ben light displacement “production”yacht, most of those with suitable drafts have bulb or wing keels. After reading your replies I am seriously contemplating give the younger girls a chance.

I am note sure a modern lightweight fin keeled yacht is designed to bounce and dry out on a regular basis. It’s not just the keel bolts that need to worry about, but the hull structure. An old fashioned longish fin keel can probably take more punishment than a narrower chord, more modern, fin keel. Personally I don’t think modern fin keel boats are designed to dry out twice a day for 6-12 months a year. I certainly would not want to do this with my own boat.

 

[Chiara’s slave]

Pointless I daresay to suggest that a multi of some sort might fit the bill best?