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Old 06-10-2015, 05:54   #16
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Re: Looking for opinions on twin keel boats vs single

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A steel twin keeler ran aground after dragging her anchor. She sat there on the Rocky shore for half an hour while we organised a tow. Didn't lay over and get pushed further up the rocks like a single keeler would have.

We pulled her of easily and reanchored her. With no damage or fuss.

The owners where not to concerned. If we hadn't got her off before the tide dropped to far they would just have sat there happily until the tide returned.

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That ability, plus the ability to possibly go to shallower waters, plus the ability to dry out easily for maintenance and the ability to stay level when in shallow tidal areas, seems appealing to me.
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Old 06-10-2015, 09:09   #17
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Re: Looking for opinions on twin keel boats vs single

I have a Hurley 22 shoal draft (90cms) bilge keel boat; she sails brilliantly and is great fun to dry out when sailing around in shallow creeks and coastal areas. My home waters are the Thames Estuary and East Coast of England which are very tidal. But you have to actively sail her all the time; impossible to keep in a straight line by sail trim, lashing the tiller and so on, and she is especially wayward downwind in a following sea. Inexperienced crew have trouble keeping her to a course. The more modern deeper twin keels are probably better in this respect. Overall, my view is 'perfect for coastal and river exploration, not so good for voyaging and longer passages.'
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Old 06-10-2015, 09:48   #18
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Re: Looking for opinions on twin keel boats vs single

I remember Benetau having a 323 Oceanias model with either a fin, shoal, and twin keel option. I have sailed the shoal but, not the twin. Their boats sail nice.
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Old 06-10-2015, 10:20   #19
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Re: Looking for opinions on twin keel boats vs single

Performancewise, and at any point of sail, bilge keelers are as good as single fin keelers if hull and keels are properly designed.
Bilge keels should be thin, with a depth/width ratio of 3/1, and the ballast concentrated in the bulbs at the kells' lower ends.
Note : This applies just as well to single keels
Bilge keels should also be angled a few degrees inward so that the incidence on the lee bilge keel is higher than that of the weather bilge keel.
When beating, heeling by say 25 degrees, both keels are in the water.

In France the RM boats , designed French naval architect LOMBARD perform extremely well.

Because the lee bilge keel drops as the boat heels, bilge keelers enjoy a shoaler draft (when beeching, not when heeling)
And standing straight on 2 keels and rudder is very convenient in many instances . eg : Secluded anchorages drying at low tide, working on the prop, painting the hull, wintering on dry ground...)

Bilge keeler with traditionnaly thick bilge keels perform significantly worse
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Old 06-10-2015, 10:22   #20
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Re: Looking for opinions on twin keel boats vs single

I have owned both fin (single) keel boats and bilge (twin) keel boats, there is nothing inherently unsafe with a twin keel boat and your choice comes down to the type of sailing you want to undertake.
Bilge keelers will not point as high into the wind as a fin keel boat will, other than on this point of sail there will be little if any difference between their sailing abilities. If you want to buy the boat to go racing, then a fin keel boat will be your first choice and you would only chose a bilge keel boat if your mooring dictated that it was absolutely necessary.
If your boating is of the “pottering” type sailing in shallow waters or in areas with a large tidal range, then the ability to take the ground without falling over or resorting to legs will give you a tremendous peace of mind and the ability to explore areas unreachable with a fin keeler.

Bilge keel boats are very popular in the UK, the Channel Islands (British not US) and on the north coast of France, where there is a large tidal range, up to 40ft in the Channel Islands and parts of the north coast of France. Westerly Yachts and Moody were two well known builders who both made good quality boats. Both companies no longer exist any more and the popularity of marinas has led to a fall in the demand for bilge keelers.

Other advantages of a bilge keeler are drying moorings tend to be cheaper and easier to maintain than deep water moorings and considerably cheaper than marinas. DIY maintenance is easier as the boat can be easily grounded to carry out anti-fouling, inspect the bottom etc. rather than having it hauled out or finding a harbour wall to lay against.
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Old 06-10-2015, 10:26   #21
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Re: Looking for opinions on twin keel boats vs single

Spent a lot of time looking into this issue since I would really like to enjoy the range of a shallow draft boat in skinny water. Some useful info in past threads here on CF. But, I have come to conclusion that a hydraulic swing keel (can be set to hold keel in down position) w twin rudders (heavy duty ss stock) for beaching is the answer. Bilge keels, even closely set, as mentioned above, create too much drag, too much wetted surface. Good luck w whatever decision you make. Cheers, Pappy
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Old 06-10-2015, 10:26   #22
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Re: Looking for opinions on twin keel boats vs single

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Performancewise, and at any point of sail, bilge keelers are as good as single fin keelers if hull and keels are properly designed.
Bilge keels should be thin, with a depth/width ratio of 3/1, and the ballast concentrated in the bulbs at the kells' lower ends.
Note : This applies just as well to single keels
Bilge keels should also be angled a few degrees inward so that the incidence on the lee bilge keel is higher than that of the weather bilge keel.
This goes against everything I've read and heard of bilge keels along with basic physics.

It may not be a big performance difference but all else being equal, the single keel should outperform.

Do you have any comparisons? I'd be curious to if I'm wrong.
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Old 06-10-2015, 11:12   #23
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Re: Looking for opinions on twin keel boats vs single

My brother sailed the Westerly Centaur "Look Far" around world in the early 80s including a triple crossing of the Tasman. On his return to Puget Sound the boat was eventually sold to a school teacher who took her for another go around with little refitting necessary.

The ability to go into shallow estuaries along the east Australian coastline or to get way back in the mangroves when the big blow hits in the tropics, to a large extent, makes up for their lack of great windward performance.

Gentleman and women vastly prefer the dead down wind or broad reaching routes anyway.

My concern with these boats, for serious offshore cruising, is not with the bilge keels per say but with the more vulnerable rudder (s) directly aft of them.
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Old 06-10-2015, 11:26   #24
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Re: Looking for opinions on twin keel boats vs single

I owned a Westerly Centaur ketch in the UK and sailed her down to Turkey. A lovely boat, with obvious advantages for shallow water and tidal areas. Windward performance is not as good as with a fin keel, and I found keeping her on track down-wind in a lumpy following sea a challenge. I don't know whether that was because of the twin keels or other design issues.
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Old 06-10-2015, 13:04   #25
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Re: Looking for opinions on twin keel boats vs single

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I've always liked twin keelers, the ability to dry out anyplace flat, and the great protection the twin keels give the hulls from rocks are two big plusses.

There is a theory that they may cause a boat to trip and capsize slightly easier in beam seas, but why would you lie beam on to any big seas? They are reported to track better than a single keel, and not roll quite as much, so that might be a benefit.

A great book about a 32 foot wooden twin keeler that sailed deep down to most of the Sub Antarctic islands on the way around the world is the Totorore Voyage by Gerry Clark. The twin keels saved him on many occasions when he dragged anchor onto some rocks, but he did end up dismasted and got rolled 6 times at one stage. Certainly an epic tale of survival and perseverance, and a testament to what a small twin keeler is capable of.

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I met Gerry Clark when he was building Totorore at his home in Keri Keri, Bay of Islands; northern New Zealand. Totorore was a modified Nova designed by NZ's Alan Wright. Gerry altered the design to form a clipper bow incorporating a bowsprit thus lengthening the original 28' overall design. Gerry showed me his boat under construction in a barn on his small farm. He had fitted a fairly large engine in the center of the boat at that stage. He also strengthened the hull with extra stringers etc. Gerry was a great believer in bilge keels and certainly sailed in extreme conditions in sub Antarctica. Unfortunately he and his crew of 1 eventually went missing. It was determined that they had been sheltering in the sub Antarctic Snares Islands south of NZ. Perhaps the wind suddenly changed trapping him there as some wreckage of Totorore was later found at the top of (I think they were) 100' cliffs. Gerry's mission as he had told me was to chart bird life in the sub Antarctic islands. Gerry had an earlier smaller bilge keeler around 26' as I remember. He circumnavigated NZ in it. Near the Chatham Islands he was stranded on a reef. Being a bilge keeler there was little damage and he was washed off by a large wave. Alan Wright designs often incorporate a bilge keel option. He is a highly respected designer of mainly cruising yachts.
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Old 06-10-2015, 13:04   #26
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Re: Looking for opinions on twin keel boats vs single

I sail a twin keel Seawolf 30 and enjoy it a great deal, the prior owner sailed her from England to Greece and throughout the Med. Then to the Caribbean and cruised the islands, where I purchased her. I am just day sailing so far on her but plan to cruise soon. I have sailed with people who have many many years of racing and cruising experience and they agree that this twin keel sails very close to the wind and does not seem to sacrifice any speed in comparison to an equivalent single keel.
Twin keel seems slightly more tender but well within comfortable parameters.
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Old 06-10-2015, 13:37   #27
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Re: Looking for opinions on twin keel boats vs single

I don't speak French but this guy (Into the wind | Un bateau , un piolet , un parapente , un tour du monde . . .) has been having quite an adventure on a newer design (Maree Haute) bilge keeler. Across the Atlantic and now around into the Pacific the long (and "wrong") way. Here seen up the Amazon River:

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Old 06-10-2015, 14:10   #28
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Re: Looking for opinions on twin keel boats vs single

Re the issue of exposed rudder(s) on bilge keelers:

Seems to me that when the design parameters include deliberately drying out the boat and standing her supported by keels and rudder(s), the NA would make the rudder structure very robust... much more so than on a conventional hull. I reckon this would help resolve any exposure issues. None of the respondents who have sailed these boats have mentioned rudder damage...

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Old 06-10-2015, 14:51   #29
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Re: Looking for opinions on twin keel boats vs single

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My brother sailed the Westerly Centaur "Look Far" around world in the early 80s including a triple crossing of the Tasman. On his return to Puget Sound the boat was eventually sold to a school teacher who took her for another go around with little refitting necessary.

The ability to go into shallow estuaries along the east Australian coastline or to get way back in the mangroves when the big blow hits in the tropics, to a large extent, makes up for their lack of great windward performance.

Gentleman and women vastly prefer the dead down wind or broad reaching routes anyway

My concern with these boats, for serious offshore cruising, is not with the bilge keels per say but with the more vulnerable rudder (s) directly aft of them.
Bilge keelers are often designed with a skeg protecting the rudder for that reason. No one design has got every aspect perfect. You decide on what you want to do and where you want to sail.

If a bilge keel boat had 2 high aspect fins with a deeper draft no doubt it could sail as well as a fin keel boat. But then it wouldn't be shoal draft and it wouldn't be stable aground.

I think it's more the fact of larger wetted area and higher COG that bilge keel boats don't point as well as fin keel boats. Perhaps a single fin with the same wetted area and same draft and COG would sail in a similar fashion. But that theoretical single keel boat would fall on its side aground.
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Old 06-10-2015, 14:58   #30
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Re: Looking for opinions on twin keel boats vs single

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This goes against everything I've read and heard of bilge keels along with basic physics.

It may not be a big performance difference but all else being equal, the single keel should outperform.

Do you have any comparisons? I'd be curious to if I'm wrong.
I think you are right and side by side around the cans on a Sunday morning race then the deep fin will probably win.

However, back in the real world, a new Genoa would make a much bigger difference as would a keen crew with performance in mind against say a retired couple just bobbing along.

The design of bilge keels for the UK market has come along way over the past 50 years. What started as almost stub keels or flat steel plates to stop yachts falling over when the tide goes out has developed into aero foil shaped fins which are towed in to provide extra lift when hard on the wind.

There are a couple of down sides. My prop doesn't have 2 tonnes of steel in front of it for protection, so we take extra care looking out for lobster pots. Drying out on a steep river bank could be a real disaster as she could go over further than a keel yacht.

However, with 5m tides being able to take the ground then sail on wet grass with a draft of 3ft 8" more than makes up for a slight loss in windward performance.

In the UK second hand prices of bilge keel yachts are higher than identical fin keeled yachts reflecting the local demand.
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