Dinghys with keels
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Category: General
Forum Name: Choosing a boat
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URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=12626
Printed Date: 05 Aug 25 at 12:38am
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Topic: Dinghys with keels
Posted By: Sam.Spoons
Subject: Dinghys with keels
Date Posted: 18 Jan 17 at 9:42am
| Not sure where to put this one but I was watching the 2.4s training on Sunday in 15-20 knots and thinking about Eric Twiname's classic bit of dinghy advice about sailing the boat flat. Obviously the 2.4 is a full on keelboat so I assume the hull form is designed to sail well at 45º+ of heel. Dinghies are designed to be most efficient with less than, say, 5-10º heel. So what about 'dinghy keelboats' like the VXOne (and bigger 'sports boats' like the Melges 24 et al). I guess their hull shapes cover the spectrum from VXOne (pure dinghy hull, hiked like a dinghy, best sailed flat) and optimised for increasing angles of heel as they get bigger and crew weight becomes a smaller percentage of the whole? |
Replies:
Posted By: zippyRN
Date Posted: 18 Jan 17 at 11:51am
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i think you've recognised the funamentals of it if you look at Uffa's smaller 'Flying' boats , the 15 being the best known they are dinghys with keels , ditto something like the Tempest ... I suppose there is a line to be drawn with regard to whether the boat is hiked ( or trapezed) or whether it has guard rails / wires and the windward side self moving ballast sits facing outwards ... |
Posted By: Sam.Spoons
Date Posted: 18 Jan 17 at 12:08pm
| Yes, that's what I was thinking, Ultra 30s and their ilk being an extreme case in one direction. It was a reference to the VX-One and looking at the Yachting World video review that set me thinking today. Just a skiff with a bit of lead in the daggerboard by the looks of it. |
Posted By: blueboy
Date Posted: 20 Jan 17 at 6:07am
| FF is not a dinghy. It is a keelboat. There are no dinghies with keels. If it has a keel it is a keelboat. |
Posted By: Rupert
Date Posted: 20 Jan 17 at 8:00am
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I think the OP knows that...
I seem to remember that Paul Handley designed the K1 to work well when heeled. Bet they sail them flat, though! The rig must be more efficient upright even if the hull is good heeled. ------------- Firefly 2324, Puffin 229, Minisail 3446 Mirror 70686 |
Posted By: Wiclif
Date Posted: 20 Jan 17 at 6:26pm
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The K1 is quite narrow, and since you don't get that same build up of weather helm with a narrow boat when heeled, this means that the tiller still feels quite light, even at the normal 30 degree heel if it is breezy.
And the keel isn't really going to keep the boat upright until it heels a bit, so it just works. But yes, you still want to keep it as flat as possible, though with 11 sq m of sail it is not underpowered |
Posted By: Sam.Spoons
Date Posted: 20 Jan 17 at 6:35pm
| My take is that a fixed (i.e. non canting) keel has zero righting moment when the boat is flat/upright so it's impossible to sail a keelboat flat without moving ballast (or 'crew' as it's known) on the windward side. Even in a drifter there will be a little heel. The effect of the ballast will depend on a number of things including how far from the centreline they can get and weight relative to the displacement of the boat and it's ballast ratio. So 10 blokes wiring of the racks of an Ultra 30 make a huge difference but a couple sitting on the windward rail of a J24 have a relatively small (but obviously still useful) effect. |
Posted By: zippyRN
Date Posted: 23 Jan 17 at 5:13pm
i think you've missed the point of the OPs question despite the hull form of the Flying boats , despite the fact that everyone from Uffa onwards sails them like dinghies in terms of 'flat ' being fast ... and we've seen subsequent designs of that nature of a hiked / trapezed planing keelboat that sail in dinghy like manner ( although the last 30 or so years of ULDB yachts had muddied the hull form waters especially with regard to planing like behaviours )
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Posted By: Sam.Spoons
Date Posted: 23 Jan 17 at 5:33pm
| Those Vendee Globe boats look like huge dinghies when their doing 25 knots + off wind. I wonder how long it takes to tack one...... the list of tasks must run :- pump the ballast from one side to the other, cant the keel, lift the windward daggerboard and lower the leeward one, turn the boat and re-sheet the foresail..... And probably several other jobs too. |
Posted By: ColH
Date Posted: 06 Feb 17 at 8:14pm
It can plane though - it's a bit odd but a real buzz. Like the 470 - maligned for being 'old hat', but still very classy, and unrivalled by many of the newer classes despite being decades old.... |
Posted By: Rupert
Date Posted: 06 Feb 17 at 9:10pm
I thought it was the Topper that was old hat?! ------------- Firefly 2324, Puffin 229, Minisail 3446 Mirror 70686 |
Posted By: Sam.Spoons
Date Posted: 06 Feb 17 at 10:04pm
Vendee Globe IMOCA 60s can plane, they can certainly travel at well over twice their hull speed and I don't think anybody would argue that there are not keelboats........ They definitely ain't dinghies 
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Posted By: zippyRN
Date Posted: 06 Feb 17 at 10:11pm
which is why the FF ( and the other small flyingboats) and other similar in conception planing, hiked or trapezed keelboats are viewed as 'dinghies with keels' - as they are compared to the laedmine era racing keelboat, ULDB in yachting has changed that somewhat.
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Posted By: ChichesterHiss
Date Posted: 19 Feb 17 at 4:31am
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As someone who has sailed Flying Fifteens on and off for 30+ years...the FF is not a dinghy with a keel, it is a keelboat with a keel! The "Dinghy with a Keel" phenomena describes the ultralight sports boats, typically with a skiff shaped hull, bulb keel and low freeboard that plane downhill like a dinghy. They include the Viper 640, the K6, the VX, the Open 570 (in France), and the Shaw 650 (Australia). I flew to Bermuda to crew with my brother in the Viper 640 Worlds last November. In answer to the OP. Upwind in lighter air, you sail these kinds of boats with a slight amount of heel and then as flat as you can as the breeze picks up. Yes, you use crew weight up to force 3, but by upper end of force 3/force 4 and above you are fully hiking and using kicker and main sheet to keep the boat flat. The boats are mildly athletic upwind but surprisingly comfortable, way more comfortable than hiking in many keel boats. In the bigger winds, we sailed upwind cracked off the breeze a bit, dead flat and we were really ripping. Downwind, it is all about sailing flat. Not much crew weight involved, its all about angle and staying on the plane . Two thoughts occurred to me on the way home. These classes have really taken off in the USA and Australia. Half the classes I mentioned in my list above are built in England and yet they are all sold abroad...why havent these classes taken off here? |
Posted By: patj
Date Posted: 20 Feb 17 at 6:50am
Maybe because the shore handling and launching is more time consuming, awkward and off putting and they are somewhat longer than most dinghy clubs allow? |
Posted By: blueboy
Date Posted: 20 Feb 17 at 7:43am
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"why havent these classes taken off here?" The K6 did, up to a point. It has or certainly had a nationals. In UK conditions you need two large males to hold it down in any kind of breeze, or crew of three but the systems are designed for two. As for the others, no traction because the SB20 (ex SB3) is the incumbent class in that market space, although numbers are very small compared to its peak. I've sailed them a few times. They are a PITA to launch like a dinghy and yacht-expensive to dry-sail from a marina. The only practical way to launch them is with a crane and not many clubs have that facility. Royal Southern YC is the only club I know of with a crane but it doesn't have that much storage space. |
Posted By: ChichesterHiss
Date Posted: 20 Feb 17 at 1:30pm
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I want to amend an earlier comment of mine. Although the FF is fundemental different in several important ways from the Viper640, K6 etc etc , it was way ahead of its time. Compared to the keel boats of the era it was and is a dinghy with a keel. Uffa Fox was a genius! The comment about the SB20 got me thinking. The sail plan of the FF may not look as modern as an SB20 but at 20 feet, the FF is a lot lighter and in some ways more dinghy like than an SB 20. So I suppose we should credit the FF as the original "dinghy with a keel". I hear the purists start muttering "if it's got a keel it isn't a dinghy" . But there is a category of boat that does not fit it well with either dinghies or keel boats. They are tremendous to sail. They sail in a groove upwind a bit like a keel boat. They plane downwind like a high performance dinghy without the drama. So the category name of "dinghy with a keel" is as good as any.
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Posted By: ChichesterHiss
Date Posted: 20 Feb 17 at 1:51pm
Blue, you are correct. There are (or at least there were) K6s at Hayling Island SC near me and I recall reading they had a decent turn out at their Europeans on Lake Garda. It looks like a nice boat and I should try and get out on one. BUT to put this in perspective, I had just come back from racing with 43 Vipers on one start line on Great Sound , Bermuda. It was an incredibly good time. I was slightly jealous and I look forward to having somethiing similar in scale here. I accept we will never have Dolphins surfacing by the Committe boat in Chichester Harbour any time soon, but this category of boat would work for a lot of people. |
Posted By: blueboy
Date Posted: 21 Feb 17 at 5:28am
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I was seriously considering buying a K6 at one time and sailed one a few times. What finally put me off was the thought that either I needed to find a really large male crew or else sail it three-up, which some do but there isn't really a job for the third person because the boat is laid out for two. What has killed the sportsboat scene in the UK IMO is that the marinas have continued to ratchet up the dry-sailing cost 5% a year every year regardless of recession or the lack of inflation, and on the whole clubs don't have crane launching. Routinely launching something like an SB20 or a Viper off a road trailer into cold salt water requires a dedication and a willingness to spend time on trailer maintenance which not many people will sustain. Said with feeling as I have done both the launching and the ensuing changing of trailer bearings. I owned a FF for several seasons. It's a keelboat, a nice sensitive one but still a keelboat, not a "dinghy with a keel". Try pulling one up the beach if you doubt it. Try capsizing one, it's been done but you really have to work at it. |
Posted By: Peter18
Date Posted: 21 Feb 17 at 8:44am
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Why not take a look at the Seascape 18. Easy to sail 2 up but room for 4. 500kg all up weight, fully lifting keel by winch inside small cabin. As easy to launch as a dinghy, trailer with no brakes and sealed bearings, carbon rig and spars, square top main, roller jib, asymmetric spinnaker with take down deck shute (dinghy style).
UK Nationals this year in Plymouth. Huge race circuit in Europe. |
Posted By: ChichesterHiss
Date Posted: 24 Feb 17 at 2:05pm
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Blue: I think my posts agree with you regarding the FF. I sailed them for a long time dating back to Broxbourne Sailing Club. I posted earlier that a FF is a "keelboat with a keel" and distinctly different from the Viper 640 and K6 category of boat. I decided to amend my comment...because:- 1. I wanted to recognize that Uffa Fox was ahead of his time, and in its day the FF was the most dinghy like keel boat around. 2. The FF sailors are very fond of calling the FF a "dinghy with a keel"....just check out the FF website. I understand where they are coming from. It is a very lightweight keel boat, even compared to the SB20. 3. It is still a lovely boat and I have many close friends who sail them. BUT I agree with you, compared to the modern era of Vipers and K6s and the like.....the FF behaves more like a keelboat. When I sailed FFs (and Solings, many years ago) I used to say to myself "Why doesnt someone design a keel boat that really takes off downwind and planes?" Solings especially were beasts in big breeze going downwind. When I stepped on the Viper .....it was one of those "Ah Ha" moment. Finally! Where I disagree with you is comparing the SB20 to Viper or K6 category. The SB 20 is much heavier and pushes a lot more water around when it is sailing. It feels very different. Not better or worse, just very different. When it comes to launching on a ramp, the lightness of the Viper made it easy. It wasnt my trailer but they looked as robust as a typical salt water trailer. I cannot speak to the K6 or VX but since they are lighter even than a Viper, I assume they must be equally easy to ramp launch. I intend to try a K6 because there are a few around locally. |
Posted By: ChichesterHiss
Date Posted: 24 Feb 17 at 2:11pm
| 70 years ago! (my god), this was as close to a dinghy with a keel as you could get: http://www.yachtsandyachting.com/news/194491/70th-anniversary-Flying-Fifteen-celebrations |
Posted By: pompeysailor
Date Posted: 24 Feb 17 at 4:02pm
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launching at many sailing clubs prevents the many Keelboat/Dinghies with keels from taking off. The reason is launching from a road base - heavy, ruins the bearings and someone always needs waders etc. and also the need for immediate depth close to the shore. How about a design where the actual bulb can be raised/lowered seperately from the centerboard (which can also be raised/lowered indepndantly from the bulb so allows the boat to be launched from a trolley & sail away from the shore without needing 4/5 ft under you so keel/bulb can be set in place? Now doodling on my notepad.. ------------- Formerly - OK 2145 Phantom 1437, Blaze 819, Fireball 14668, Mirror 54145 |
Posted By: Peter18
Date Posted: 24 Feb 17 at 5:27pm
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The Seascape 18 has a lifting keel which is raised by a permanent winch in the small cabin. The keel retracts fully flush into the hull and can be progressively wound up or down dependant on the depth of water, so ultra easy launching and no need for depth of water close to the shore. Plus the rudders are in cassettes and can be easily raised or lowered.
Also its roller trailer has no brakes (under the weight limit) and has sealed bearings. The seascape 18 is probably the best option when looking for a dinghy with keel. Check it out at wwwthinkseascape.com |
Posted By: ChichesterHiss
Date Posted: 24 Feb 17 at 9:54pm
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Peter........I totally respect your enthusiasm for your product. But since you posted your ad twice, I just want to point out that its a different animal from the K6, VX and Viper performance category. (and I realize there are others like the Open 5.7 and the Aussie T boats but these three are readily available in UK and built in UK) . These three have low free board and Sail area to weight ratios (SQm*10/ Kilo) of 1.8- 2.1. They go upwind like a keelboat (caveat I havent sailed all three but looking at pics) and tear downwind like a planing dinghy. The Seascape to me looks like a keelboat/little yacht that can be launched off a ramp. It looks much more like a smaller version of a J70, SB20 or Melges 20 than the dinghies with keels. It has an SA/Displacement of 1.1 and downwind, the pictures show a lot of water being moved. I think that someone stepping off a J80 might be entertained in terms of performance but someone stepping off a Merlin or a Viper might be disappointed. It doesnt mean one is better or worse but different. I would enjoy trying it. In fact I would definitely come to a "sail off" if someone organized getting all these boats in one place so we could step from one to another. But yes.....I like the cassette rudder feature. The bulbs with keel up only add 4 inches to draft, but its the cassette rudder that really enables easy on/off from the ramp. Pompey......I understand the care-of-trailer argument but not sure I understand the wading argument. I need to wade whatever boat I launch from a ramp whether it is an RS 200 or something else. Is there something Im not thinking of as I try and imagine launching a K6 . By the way....yes there are plenty of clubs I can think of where keeled dinghies would be non-starters. |
Posted By: Sam.Spoons
Date Posted: 24 Feb 17 at 10:49pm
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Interesting, I hadn't cottoned that Peter18 was the Seascape 18's principle. I feel slightly less guilty about pointing out that it costs €30,000 (does that include a trailer and other 'optional' bits?) and the 2016 UK Nationals attracted, I think, 5 boats. It's a nice looking boat but, as has been said, more on the 'fast cruiser/racer side of the sports boat genre than a big dinghy. edit :- TBF though, it is pretty light. Just thinking about this...... So to be classed as a proper 'keeled dinghy' it should be capable of being launched by one man into knee deep water (which should be possible at any dinghy club)? I can't see a problem with a Stratos Keel, Bosun or such like, a boat you would routinely take out of the water at the end of a days sailing but I also see the logic in describing an FF in such a fashion and dry sailing one of those is another ball of wool. When I started this thread I was thinking of how a boat performed/handled but maybe that shouldn't be the defining point. Not that it matters really, these days all the lines are blurred in a way that would have been unthinkable 20 years ago.
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Posted By: blueboy
Date Posted: 25 Feb 17 at 12:31pm
I'm not certain I did compare the SB20 to the K6. Viper......the question is why it has gained no traction at all in the UK whereas it did in some places elsewhere, notably the USA. I'd argue that the the incumbent presence of the SB20 prevented that. The hopeless marketing was another factor, I made a number of attempts to get a test sail when Rondar had a test boat on the south coast and never got a call back.
Having owned a FF I know quite a few FF sailors and not a single one has ever said that in my presence!
I've launched one (as crew, not owner) from a ramp and it seemed pretty straightforward. Easier than launching a FF off a lee-shore which can definitely be an acquired skill. |
Posted By: Riv
Date Posted: 25 Feb 17 at 2:55pm
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Many years ago I was a member of oxford sc and they used to lifeboat launch Ffs. They tied a rope to the trolley so it would'nt end up off the ramp, then jumped in and let it roll. Worked for the lee shore problem.
On another point I remember an Rya coach explaining the difference between keelboats and sports boats. Kbs have a keel that is not normally removed and can be a structural part of the hull. The Ff fits this description even if Uffa did unbolt the keel and stick it in his car boot and car top the hull. Sb20s and so on have removable keels and therefore are Sports boats, much more dinghies with keels than the Ff Royal Torbay has a crane and a small fleet of Sb20s and Ffs |
Posted By: rb_stretch
Date Posted: 27 Feb 17 at 8:14pm
As an ex sportsboat owner the biggest issue is cost. Small keelboats incur yacht like costs for mooring. For example a 20ft dinghy such as an FD might cost £300 dinghy storage, wherease a 20 foot keelboat will cost £3000 for dry sailing or a marina. In country with less pressure on shore side space I believe the mooring costs are considerably cheaper. |
Posted By: Sam.Spoons
Date Posted: 27 Feb 17 at 10:16pm
| It's cheaper up North, and somewhere else on here someone said that 20% of marina berths are vacant. But a berth in Glasson Dock is to much use of the racing is in the Solent..... |
Posted By: blueboy
Date Posted: 28 Feb 17 at 5:33am
Think 50% more than that, on the south coast anyway. |
Posted By: ChichesterHiss
Date Posted: 01 Mar 17 at 1:55am
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I am not convinced by the "cost" argument.....and perhaps that is because I am coming at it from the angle of a Viper or a K6 as an alternative to a keelboat. I am hoping that the "dinghy with a keel" category of boat will be less money to run than an SB 20 sports boat because they truly can be ramp launched.....and a whole lot less to run than an X boat or an Etchell. These boats are much lighter than sports boats like J 70 etc. they also come with dinghy trollies on their trailers. I have seen lots of pics of Vioers being ramp launched and towed behind average cars. Anyway, I will find out when the weather gets better, because I am going to investigate myself.
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Posted By: ChichesterHiss
Date Posted: 04 Mar 17 at 4:05pm
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Googling Vipers VXs and K6s and I came across this: https://Yachtscoring.com/current_event_entries.cfm?eID=2996" rel="nofollow - https://Yachtscoring.com/current_event_entries.cfm?eID=2996 They have 54 entries for an event in October and the entry list has only been open for four weeks. I would love for this category of boat to be more active over here. 10 years ago the American one design classes had a reputation of heavy outdated boats while the GBR sailor was seen as more ready to seek high performance . The yanks have either caught up or overtaken. |