Thoughts on adding dagger/s board to Lagoon 57

[canadian cat]

Lets hear peoples thoughts on adding at least one dagger board (maybe two) to a lagoon 57 (the first version) and removing the keels. I don't own a 57 but it is in my sights as a boat with lots of good atributes.

First off lets assume it has nice perfomance sails (I used to work for North) and the boat has been put on a major diet. Ie. no genny, lifePo batteries, removed equipment from two bathrooms (or deleted all together), no A/C.

The hull beam to lenght ratio is not bad at 10.5 the displacement is not too heavy at 13 tons.

My plan would be turn the port hull into an owners cabin with only one forward head and shower, no crew quarters to lose weight and then add one dagger board.



If you compare a Lagoon 57 to a similar Catana the weight is good, the price is good. The sail area is a bit short, but that can be fixed. I see it as missing a dagger board.

[Factor]

Originally Posted by canadian cat

If you compare a Lagoon 57 to a similar Catana the weight is good, the price is good. The sail area is a bit short, but that can be fixed. I see it as missing a dagger board.

You sure the 57 is 13 Tonne? These are manufacturers claimed lightship displacements. (outremer will contract to that weight, so that one is definitely believable)

Outremer 5x - 13 tonne
Catana 59 - 19 tonne
Lagoon 560 - 30 tonne
FP Sanya 57 - 21 tonne

So the L57 is in Outremer 5X territory. And thus should outperform most boats - with or without daggerboards

[barnakiel]

Everything is doable. At a COST.

b.

[canadian cat]

Factor what you say is true. Who knows what the 57 weights in at. Real info is hard to find. The older 57 was built by the specialist JTA with carbon and whatever that means to how much it weights and how well it was built. Even if it is in the range of the other boats. To lose weight, add nice large sails, and a dagger board. Is the 57 worthy of any performance mods? Also, is this kind of modification going kill resale?

Originally Posted by Factor

You sure the 57 is 13 Tonne? These are manufacturers claimed lightship displacements. (outremer will contract to that weight, so that one is definitely believable)

Outremer 5x - 13 tonne
Catana 59 - 19 tonne
Lagoon 560 - 30 tonne
FP Sanya 57 - 21 tonne

So the L57 is in Outremer 5X territory. And thus should outperform most boats - with or without daggerboards

[BigBeakie]

There is a thing called hydrodynamics that is involved in hull design. Very important stuff. Many factors go into a hull design to achieve a desired outcome, like sailing performance for example, and just chopping off some keels and replacing with a daggerboard may well be a fruitless exercise, if not counter-productive. A hull length to beam ratio of 10.5 isn't that great either, it's obviously meant to favour load carrying vs performance. Now if you had a hull length to beam of 12:1 or 12.5:1, then you could chase some increased performance by reducing the wetted surface area with such a strategy. Even so, this would be a high risk experiment it seems to me.

This is a serious question for a multihull naval architect or a good multihull designer who has the math & engineering smarts, rather than gathering opinions from a forum audience, surely?

Would you go ahead with this if 10 CF responses said "Great idea, go for it!"

[django37]

I believe it will be a waste of money. New sails, clean bottom, getting rid of useless stuff will make the boat much faster - and of course: learning to sail the boat.. The Australian OMR, says that daggerboards will make your boat 0.5% faster for the same weight, but your boat will be heavier with daggerboards, that are strong enough.

[Dulcesuenos]

I don't think anything will make them faster short of surfing down a huge wave or a jet engine loll. We played with a 50 watching these guys do everything they could for hours to eek more speed in 17knots of wind and couldn't break 7 knots. Its a cruiser , not a perf cat

Sent from my LG-LS980 using Cruisers Sailing Forum mobile app

[yeloya]

Doing it properly will cost you a lot of money. In turn, it can have marginal effect on speed. The main benefit will be in giving less leeway when sailing upwind.
Some naval architects are suggesting that the fixed keels can be very dangereous when a big and breaking wave hits from the side of the boat, leading to trip the boat over. (With dagger boat retracted, in simlar conditions the cat would skid away..)
If you are planning to sail in Southern Ocean or in the high lattitudes, you may want to give another thought, otherwise forget it ..

Cheers

Yeloya

[canadian cat]

Hey Beakie

Take a chill pill I post here for conversation about catamarans. My wife doesn't want to talk about cats as much as I do.

Originally Posted by BigBeakie

Would you go ahead with this if 10 CF responses said "Great idea, go for it!"

[canadian cat]

Is everyone talking about the old Lagoons or grouping all old and new together? This is the boat that I am talking about.


From my understanding the newer boats are much heavier. What I am trying to find out is do they sail ok now and good new sail, a diet, and a daggerboard will make them sail upwind in light to med. conditions well?

Is a daggerboard boat going to be faster all the time no. The board will only help in light to med up wind conditions (more lift) and downwind with less drag and as stated in storm conditions for sliding down waves.

[Tingum]

This is a much bigger deal than you realize. First off a good multi hull naval architect would have to both design the placement AND the structural strengthening of the hull. It would most likely require tearing up the interior to access the hull and the structural placement of the trunks. Most likely cheaper to buy a different boat!

[1ercru]

Canadian cat, I see you are back at it again. Just BUY one and get it over with, you are clearly in love! and with those looks who among us can blame you!

Since there are few actual sailing experiences forth coming on these yachts here at CF. Perhaps a quick email to some of the charter captains still operating these boats for some real experience and recommendations. If that feed back keeps the fire going, consider a week charter on one (how bad could that be!) certainly that will give you personal insight.

[malbert73]

Just was lucky enough to get out on a sea trial of an Atlantic 57 yesterday in 10-15 knot winds. We were consistently hitting 10-12+ knots on all points of sail without even working hard at trimming sails (purpose of trial was tweaking reef points and looking at some wrinkles in jib.
Rode like it was on rails. Chris White was along, and he definitely deserves compliments.

Now that's a performance cat. Scrap the Lagoon idea and get one of those.

[BigBeakie]

Canadian Cat,

Sorry, I didn't mean to ruffle feathers or be a smart alec; just that what you are proposing is a nice thought exercise, but to apply some caution and consult with a professional before laying down cash or plugging in the saw

You never know, someone out there may have actually done something like this (ie some experience) or a designer might pipe up and offer an educated opinion on the technical feasibility, in which case that would really help you.

Certainly the Lagoon you displayed in the photo has more potential for reasonable performance than the current condmarans, but still....

[1ercru]

Check out "ZERO" modern Lagoon 55 project boat, some nice design work, (no boards). Looks Italian now.

Federico Delrosso Architects#