Extending a Lagoon 40

[Roddu]

Anyone got any views on extending a Lagoon 40 by a few feet to improve seaway and performance? Both bow and stern, or one of these only?
We really don't need more interior space, but are looking for a bit better performance and better seaway. From experience (chartering) i get this if I go a few foot bigger, but that quickly adds +$100k to the bill, and space I really don't need. I understand that the boat will still be under-rigged with a too small main and jib....but I am wondering whether from a boat-building perspective just adding 2-3 foot to bows and stern might make sense?
Also, if anyone has a view on whether the stern extension is even feasible or makes sense (re location of saildrive and inclination of below-water line stern), please let me know as well!
Thanks!

[sailormed]

How do you increase length without adding interior space?

[Roddu]

haha, very constructive, great input and super helpful - thanks!

[arsenelupiga]

L 40 is designed by one of the best yacht architects in the world. So playing with hull shape, i would no do.

Go longer and older so you keep same dollars.

Or learn how to sail better.
L 40 similar to our L 400. In open ocean conditions has proven really comfortable . From what we enquired, out of 40 boats going over tasman to NC, we were only one with no seasickness and no complaints. And seas were decent.

Regarding performance, if you keep it reasonably light you get performance of average 45 feet cat.

[jimbunyard]

For hydrodynamic and structural reasons the only 'economical' way to do this would be to add the length in the middle. Not too uncommon (though expensive) on monohulls; the engineering bill alone on a multihull would probably be cost prohibitive...

And the same, or close to the same, results could probably be achieved by more conventional means like more efficient rigging, sail handling and weight distribution or reduction.

[Benz]

If you have it professionally done (as in adding sugar scoops aft), the cost will be in the tens of thousands, and your resale value will plummet....better spend the 100k to upgrade to a bigger boat.
If you find the seas uncomfortable in a 40-foot cat, I'm not sure they'd feel much better in a 42-foot.
I'd seriously spend the money and effort in reducing weight: titanium cookware (they have it for camping), lighter rigging (synthetic) better sails, less electronics (copper wire is heavy and adds up), only one pair of shoes apiece....you get it: weight savings is incremental, but weight means a lot in a cat.

[Sand crab]

Lots of people have added stern extensions. It was so popular on the Seawind 1000 that Seawind redesigned this cat with that mod and it became the XL. It was also done on the Mantas which started as a 38' and then grew to a 42'. I think there's vids on these. About 10 years ago some guys in France were offering bow extensions for the Outremer 50/55 and maybe the 45. It changed it to a vertical bow I think. They even built the molds. There's a Voyage 430 with 3' extensions for sale now if you want to get some ideas. It's not too complicated or expensive especially if you can DIY.

[etoimene]

I think it would be easier and cheaper to play with the rig.

Buy a bigger boat!

[LittleWing77]

Why don't you reach out to Manateeman and JimBunyard who are both boatbuilders and Forum Members. I have a feeling (with absolutely no facts to back it up) that adding "2-3 feet" to two hulls would cost in the neighbourhood of $100K or more anyway...

(Sorry - just saw that Jim has already weighed in above, although not re costs)

[smj]

[QUOTE=LittleWing77;3345597]Why don't you reach out to Manateeman and JimBunyard who are both boatbuilders and Forum Members. I have a feeling (with absolutely no facts to back it up) that adding "2-3 feet" to two hulls would cost in the neighbourhood of $100K or more anyway...

(Sorry - just saw that Jim has already weighed in above, although not re costs)[quote]
......"........................................... .................................................. ..............

We paid around $10k to have 3’ added to the sterns of our Seawind 1000. From talking to others this was the going price albeit 10 years ago.

[jimbunyard]

A Lagoon 40 is not a Seawind 1000...

Redesigning a boat from, say, a Norseman 400 to a 430 or a Seawind 1000 to a Seawind 1000XL or a Manta 38 to a 42 is not the same as sticking a bow and stern extension on an existing boat.

But it can be done, and I've done it (at the stern anyway), though not on a catamaran. I even hear they've "got some guys in France who've got some molds", so there ya go.

[smj]

Originally Posted by jimbunyard

A Lagoon 40 is not a Seawind 1000...

Redesigning a boat from, say, a Norseman 400 to a 430 or a Seawind 1000 to a Seawind 1000XL or a Manta 38 to a 42 is not the same as sticking a bow and stern extension on an existing boat.

But it can be done, and I've done it (at the stern anyway), though not on a catamaran. I even hear they've "got some guys in France who've got some molds", so there ya go.

The original Seawind 1000 stern extensions were just that, sticking a stern extension on an existing boat.

[Sand crab]

Jim, I think the Mantas were extended in the manufacturing process with new mold extensions. People liked it and then extended their own boats. Maybe someone can correct me if I'm wrong on that. The Voyage 430 stern extension was a one off done privately by the owner. There's a Brazapi with 5' extensions and a Leopard 47 with 3' extensions.

I've only seen one multi cut in half and extended in the middle and that was owned by a couple in Canada. They have vids on it.

Maine Cat did extend an MC30 to 33 by cutting and splicing. That was a special order deal on a new boat. That boat was for resold recently and went fast and that was before the covid frenzy.

I will politely disagree that a stern extension will devalue the boat. It may not add value but it sure makes it interesting to a prospective buyer.

[Shrew]

You'd be better off, and more likely less costly, to simply sell the boat and buy the one you want. It's not like putting an addition on a house. While it's possible, it's not really practical.

[smj]

There has also been a PDQ 36 that added 3’ to their sterns, a couple of Outremer 49’s and even a few Gunboats that have had their sterns extended.
Also an older Crowther 40 that cut the boat in half and added 6’.