ITA 14.99

[catmancan2]

Originally Posted by SVNeko

I looked at it. They are pretty hulls. They look grey in color. Is that gelcoat, or some sort of grey epoxy?

Thanks Neko. Nr.1 hull is a blue gray gelcoat (RAL 7031) http://www.ralcolor.com

The photo posted was prior to hull being tented/post-cured (bag-n-bake) that is now completed. Soon the hull will be sanded and polished for a high gloss appearance. Other RAL gelcoat colors are available.

[iliohale]

I had the opportunity to visit the new ITA factory in Fano Italy on Monday of this week. I was hosted by Leo and Chris from ITA and Don from the US dealer, Navigator Yachts. I took a ton of video but ITA has asked that I only share the exterior shots of the boat until Hull No. 1 is completed. I will create a video of the visit and post it on my youtube channel "iliohale Production" in the next week or so. You can subscribe to my channel to get the notice when I post it.

Here is the bottom line, in my opinion the ITA is going to be an exceptional boat on many levels and I believe it will be a reasonably priced, exceptionally well designed and built performance cruiser. It will compete very well with Outremer, Catana, HH (in the performance cruiser market - not race), and then boats like Balance and the Seawind 1600. After spending the entire day touring and meeting with the factory reps, I made some quick discovery notes of the key features and differentiation I noted while there. Here are the raw notes:

1. Hull Design
a. Bow entry
b. Flat bottom sections
c. Forward hull useable space
d. Load carrying capability – ~400KG per CM of depth
e. Bridge deck clearance
f. Overall proportions and look are exceptional
2. Structural Design
a. Wide spread use of carbon throughout the structure and bulkheads
b. Comprehensive structural analysis by independent third party
c. Watertight chambers
d. Use of robust carbon stringers
e. Integrated support in the deck mold for the main bulkhead, extremely strong approach
f. Composite sprint with integrated cross beam, no stays required and two available lengths
g. Cabin top and window design and the associated supports
h. Deck equipment reinforcement details
i. Chain plate design and execution is incredible
j. Dagger board supports
k. Weight and load capacity
3. Build Execution
a. Mold design – one piece hull and bridge deck with foredecks infused at the same time
b. Quality of the molds – extremely strong and the final pieces require very very little fairing
c. No chopped strands behind the gelcoat
d. Epoxy compatible gelcoat
e. Post layup gelcoat sanding and polishing
f. Quality of the glass work
g. Bulkhead construction and installation – very high quality work
h. All parts weighed prior to installation
i. Epoxy and post curing
j. Hull penetration detail – removal of core
k. Hull deck join – all glassed
l. Quality of the materials and parts being used is exceptional
m. Use of structural bulkheads
n. Rudder post details and support
o. Mast support details
p. Stern beam details
q. Plumbing and electrical run details with support for post-delivery installations
r. Execution of below deck running rigging runs
s. Use of light weight wood composites
t. Quality of the furniture
u. Dagger board design and execution of the adjustable supports
4. Overall Design Elements
a. Details on the foredeck lockers including the anchor and windless lockers with locations of the tank vents and fills
b. Tramp attachment detail is amazing
c. Tank locations
d. Engine and mechanical system access
e. Mechanical system design
f. Electrical system design
g. HVAC systems design
h. Running rigging design
i. Quality of all the parts being used from the tank vents to the seacocks to the major system components is very high
j. Both the owner and guest head/shower design and layout is fantastic
5. Other
a. Factory personnel and access to skilled labor
b. Support for owner semi-custom options
c. Available standard options, great choices here
d. Fano is an excellent place to commission and take delivery
e. Strong desire by the factory to deliver an exceptional boat and experience for the buyer which is rooted in the custom boat building experience of the key factory personnel
f. Factory facility and set up
g. Access to marine support vendors for post-delivery work

I would be happy to discuss and provide more detail on any of my notes if there is interest. I will also cover these on the video.

Gary

[Catmandu]

Looking forward to the videos.

[Catmandu]

I should add - what would be most useful is your "take" of each of the items listed above and how/why ITA's approach is better or sets it apart from Outremer, Balance, HH ... etc.

[iliohale]

Originally Posted by Catmandu

I should add - what would be most useful is your "take" of each of the items listed above and how/why ITA's approach is better or sets it apart from Outremer, Balance, HH ... etc.

Hey Catmandu,

Since you asked ...........

........ here is the background on why I listed the key differentiators that see in ITA 14.99. Warning, this is a little long winded but only because it is a passionate topic for me, can you tell LOL.

In full disclosure, I am not by any means an expert on catamaran design or building, just a potential buyer who has evaluated all of the boats I listed in my pervious post. Also, in full disclosure, I have yet to see the Seawind 1600 in person. Otherwise, I have carefully evaluated all these boats in person and via their sales literature as well as owner feedback via this forum and other social media. So the following should strictly be considered my opinions based only on my own evaluation approach.

Taking these by my categories

Hull Design

The hull shape of the ITA appears to be unique in the boats I have evaluated. ITA with its flat bottom sections, overall hull beam of 4.92 ft at WL, and the way the beam is carried aft from the bow and into the aft sections just looks like a different approach from the majority of the U – shape hull sections I have seen in the other boats. It is clear that this results in an excellent load carrying capacity for a performance cruiser of nearly 8000 lbs above light ship. My statement above of 400 KG per cm of hull depth is actually incorrect; it is 480KG per cm of hull depth. So the delta between light ship and full load in the ITA is less than 8 cm or 3.15 inches in increased depth. (Note the taped WL in my photos is already the estimated full load depth). It is very hard to get enough information on the other boats because the builders really play games with the light ship weights and the reported design load capacities and their impact on the hull depth. This is verses very clear information being provided by ITA. The delta between hull depth at light ship and full load is critical to understanding the potential impact on the performance at full load. But I suspect that based on the hull shape of say the Outremer, Catana, and Seawind, 4 tons of additional load will have a greater impact on wetted surface and, therefore, performance than the hull shape of the ITA. ITA has provided sailing polars showing light ship vs. full displacement performance and the design impact is very small. Of course, the proof will be in what is realized in actual sailing performance so time will really tell how well the ITA hull shape equates to light ship and full displacement performance.

Bridge deck clearance is another key factor in my opinion. ITA lists theirs at 3.02 feet. I do not know if this is light ship or full displacement. These numbers can easily be compared to the other boats and a few will have surprisingly low bridge decks. But be sure to compare apples to apples, equal light ship numbers or full design displacement numbers. It is also critical to understand how far aft the bridge decks start and ITA has started theirs very far aft which is a great advantage in terms of comfort at sea. The downside to high bridge deck clearance is overall appearance of the boat in profile, cabin top height above the deck, and wind profile. I really like the overall profile of the ITA and I think the designer has done an excellent job in creating the bridge deck clearance without impacting the profile too much. I also believe that some of the other boats I am comparing the ITA to also have nice profiles but again, some of these have been achieved with a lower bridge deck. So buyers beware.

Also ITA realizes wider hull beam further forward than boats like Outremer and HH which, I believe has benefits such as better motion at sea, easier to plane, and more usable room in the forward cabin. I am not sure of the downsides here but in my opinion this is a differentiator for ITA that I like.

Structural Design

OK, this is a very difficult comparison to summarize as I have listed so many aspects here and the comparison really varies across the boats I am comparing. Some of the comparison boats will compare well on some of the aspects I have listed. So I think you have to look at this on the whole. It is very clear to me that ITA is a step ahead on the structural design over most of my comparison boats and that they have a focus on building a very strong and light boat. While not over the top in terms of all out no compromise all carbon approach of HH (which is an option by the way), ITA is making good choices in the base materials that will yield good value for their buyers in terms of weight/strength and maintenance. In working with the ITA team it is also clear to me that these guys are highly experienced and really know what they are doing. ITA also shared with me the structural design analysis performed by a naval architecture firm which gives me a lot of confidence in the boat. Ask to see this from any of the major builders and they will likely laugh in your face.

ITA is also doing some very innovative things like their approach to building the bow sprint and integrated cross beam. I got to see this first hand with the layup of the first one and it was very impressive to me as a former structural engineer who knows something about forces and materials. Also details like the rudder tube reinforcing, chainplate with load distribution, flanges, dagger board support, main bulkhead installation, and so on was extremely impressive. Again, I am sure that some of the comparison boats will also be impressive on these design aspects but it clearly indicates that ITA is building an extremely strong boat. I also witnessed the layup of the first deck and saw how the design gets translated to the layup and the attention and oversight ITA has to the entire process. Overall, on this topic area, I have a lot of confidence in what ITA is doing. I also know that builders like Outremer and HH build good quality strong boats that owners can have confidence in. The list I provided reflects those aspects of ITA that really impressed me.

Build Execution

A significant factor in the overall quality of the boat is the quality of the molds and the approach the builder takes in regard to the assembly of the fiberglass parts. The real differentiator, in my opinion, for ITA is the design and quality of the molds. On hull no. 1 for example, ITA indicated that they used less than 2 KG of faring compound. This is an extremely small amount and it reflects on the quality of the molds which are massively reinforced, way more so than any other molds I have seen. In addition, the approach that ITA takes on the mold design is to layup the entire hulls/bridge deck and first 1/3 of the foredecks in a single infusion. This is incredible and I don’t believe any other manufacture is doing this. It is truly amazing and reflects the skill and experience of the ITA team. I know, for example, that Outremer lays up the hulls/bridge deck in 3 pieces and then brings together the outer sections of the hulls. This makes for a heavier structure and requires significantly more filler.

The fact that ITA is using epoxy and post curing is a real differentiator. This adds to the construction costs but carries a lot of value in terms of weight, durability, and strength. Other than the HH boats, I don’t believe any of the other boats I have evaluated are using epoxy. Please correct me if I am wrong. Other examples of ITA’s desire to produce an exceptional boat is reflected by details such as glassing the entire hull to deck joint creating an incredibly strong structure. This is very labor intensive and not something the majority of the other manufactures do. In addition, it is reflected by small details like their approach to installation of all thru hulls where the core is fully removed and added solid laminate to prevent any possibility of water penetration into the core. ITA’s approach to managing plumbing, HVAC, and electrical runs is outstanding and will go a long way towards creating happy owners that want to add equipment after taking delivery.

Many of the boats I have compared to the ITA also do some very fine things in regard to build execution. But again, in my opinion, overall the ITA is a level above the majority of boats unless you go very high end like the HH boats. In the ITA price range, I see no real comparison to the level of attention ITA pays to building an outstanding boat.

Overall Design Elements

ITA has a general philosophy to keep the decks as clean as possible. This is after all an Italian boat where key factory people have come from stylish builders such as Wally. So there is a real focus on implementing some very innovative approaches to running rigging, line handling, tank fills and vents, bow anchor, and installation of components such as the tramp. For example nearly all lines will be below deck in custom fitted runs including spinnaker guys, furling lines, reefing lines, halyards, and so on. All tank fills and vents will be centrally located in a locker forward of the main cabin. ITA’s approach to the installation of the tramp will use no exterior fastening and will be contained within a specially molded section.

ITA’s approach to the installation of the main cabin windows, main bulkhead, and support for the cabin top will provide a truly unique experience from the majority of the cats I have compared it to. The main cabin will have a wonderful openness to the exterior and provide fantastic views. ITA has elected to provide one head per hull, so a single head servicing the two guest staterooms in the port hull. This provides a wonderful roomy layout for the guest head unlike the cramped double head set up most catamarans provide. Both heads have separate stall showers with seats, yes actual seats in the shower. Despite the fact that the ITA is a performance cruiser, the hulls are surprising wide and do not feel cramped. Part of this is the result of the bridge deck design that allows for inboard cabinets to be set back and provide more space. Also, the design of the dagger board trunks keep them as far outboard as possible and they do not significantly interfere with fore and aft access. The port guest head is outboard and the dagger board trunk is accommodated between the vanity and the shower, completely out of the way. Also, very important in my evaluation is the capacity of the tankage on the boat. ITA has done a great job in tank placement to keep them centered in the boat, accessible, and with good capacity. This, in my opinion, is a real differentiator when compared to most the other boats we have looked at.

Further, based on the standard boat equipment list, it is clear that ITA is using very high quality components throughout right down to the smallest parts such as tank vents, furniture hardware, and thru hulls. The major components such as the HVAC, electrical, and plumbing systems are also very high end. Running and standing rigging is top end with great options to choose from.

Other

Not much to say here. Every Buyer will need to do their own evaluation to determine who they feel comfortable working with. For me, the bottom line is that you want to do everything possible to have a good experience when you make a major purchase like a large catamaran. You need to have confidence in the dealer and manufacturer to do the right thing and follow through on their commitments. Further, I plan to cross oceans with family and friends onboard, I want to have complete confidence in the vessel I am on and keep risk at a minimum. The whole experience of buying and commissioning your boat should be fun and not stressful. The US dealer and ITA Factory personnel have been wonderful to work with so far and extremely helpful. I believe I can rely on them to help me make the right decisions and deliver a safe platform to go sailing and have some fun doing it.

Gary

[catmancan2]

Originally Posted by iliohale

Hey Catmandu,

Since you asked ...........

........ here is the background on why I listed the key differentiators that see in ITA 14.99. Warning, this is a little long winded but only because it is a passionate topic for me, can you tell LOL.

In full disclosure, I am not by any means an expert on catamaran design or building, just a potential buyer who has evaluated all of the boats I listed in my pervious post. Also, in full disclosure, I have yet to see the Seawind 1600 in person. Otherwise, I have carefully evaluated all these boats in person and via their sales literature as well as owner feedback via this forum and other social media. So the following should strictly be considered my opinions based only on my own evaluation approach.

Taking these by my categories

Hull Design

The hull shape of the ITA appears to be unique in the boats I have evaluated. ITA with its flat bottom sections, overall hull beam of 4.92 ft at WL, and the way the beam is carried aft from the bow and into the aft sections just looks like a different approach from the majority of the U – shape hull sections I have seen in the other boats. It is clear that this results in an excellent load carrying capacity for a performance cruiser of nearly 8000 lbs above light ship. My statement above of 400 KG per cm of hull depth is actually incorrect; it is 480KG per cm of hull depth. So the delta between light ship and full load in the ITA is less than 8 cm or 3.15 inches in increased depth. (Note the taped WL in my photos is already the estimated full load depth). It is very hard to get enough information on the other boats because the builders really play games with the light ship weights and the reported design load capacities and their impact on the hull depth. This is verses very clear information being provided by ITA. The delta between hull depth at light ship and full load is critical to understanding the potential impact on the performance at full load. But I suspect that based on the hull shape of say the Outremer, Catana, and Seawind, 4 tons of additional load will have a greater impact on wetted surface and, therefore, performance than the hull shape of the ITA. ITA has provided sailing polars showing light ship vs. full displacement performance and the design impact is very small. Of course, the proof will be in what is realized in actual sailing performance so time will really tell how well the ITA hull shape equates to light ship and full displacement performance.

Bridge deck clearance is another key factor in my opinion. ITA lists theirs at 3.02 feet. I do not know if this is light ship or full displacement. These numbers can easily be compared to the other boats and a few will have surprisingly low bridge decks. But be sure to compare apples to apples, equal light ship numbers or full design displacement numbers. It is also critical to understand how far aft the bridge decks start and ITA has started theirs very far aft which is a great advantage in terms of comfort at sea. The downside to high bridge deck clearance is overall appearance of the boat in profile, cabin top height above the deck, and wind profile. I really like the overall profile of the ITA and I think the designer has done an excellent job in creating the bridge deck clearance without impacting the profile too much. I also believe that some of the other boats I am comparing the ITA to also have nice profiles but again, some of these have been achieved with a lower bridge deck. So buyers beware.

Also ITA realizes wider hull beam further forward than boats like Outremer and HH which, I believe has benefits such as better motion at sea, easier to plane, and more usable room in the forward cabin. I am not sure of the downsides here but in my opinion this is a differentiator for ITA that I like.

Structural Design

OK, this is a very difficult comparison to summarize as I have listed so many aspects here and the comparison really varies across the boats I am comparing. Some of the comparison boats will compare well on some of the aspects I have listed. So I think you have to look at this on the whole. It is very clear to me that ITA is a step ahead on the structural design over most of my comparison boats and that they have a focus on building a very strong and light boat. While not over the top in terms of all out no compromise all carbon approach of HH (which is an option by the way), ITA is making good choices in the base materials that will yield good value for their buyers in terms of weight/strength and maintenance. In working with the ITA team it is also clear to me that these guys are highly experienced and really know what they are doing. ITA also shared with me the structural design analysis performed by a naval architecture firm which gives me a lot of confidence in the boat. Ask to see this from any of the major builders and they will likely laugh in your face.

ITA is also doing some very innovative things like their approach to building the bow sprint and integrated cross beam. I got to see this first hand with the layup of the first one and it was very impressive to me as a former structural engineer who knows something about forces and materials. Also details like the rudder tube reinforcing, chainplate with load distribution, flanges, dagger board support, main bulkhead installation, and so on was extremely impressive. Again, I am sure that some of the comparison boats will also be impressive on these design aspects but it clearly indicates that ITA is building an extremely strong boat. I also witnessed the layup of the first deck and saw how the design gets translated to the layup and the attention and oversight ITA has to the entire process. Overall, on this topic area, I have a lot of confidence in what ITA is doing. I also know that builders like Outremer and HH build good quality strong boats that owners can have confidence in. The list I provided reflects those aspects of ITA that really impressed me.

Build Execution

A significant factor in the overall quality of the boat is the quality of the molds and the approach the builder takes in regard to the assembly of the fiberglass parts. The real differentiator, in my opinion, for ITA is the design and quality of the molds. On hull no. 1 for example, ITA indicated that they used less than 2 KG of faring compound. This is an extremely small amount and it reflects on the quality of the molds which are massively reinforced, way more so than any other molds I have seen. In addition, the approach that ITA takes on the mold design is to layup the entire hulls/bridge deck and first 1/3 of the foredecks in a single infusion. This is incredible and I don’t believe any other manufacture is doing this. It is truly amazing and reflects the skill and experience of the ITA team. I know, for example, that Outremer lays up the hulls/bridge deck in 3 pieces and then brings together the outer sections of the hulls. This makes for a heavier structure and requires significantly more filler.

The fact that ITA is using epoxy and post curing is a real differentiator. This adds to the construction costs but carries a lot of value in terms of weight, durability, and strength. Other than the HH boats, I don’t believe any of the other boats I have evaluated are using epoxy. Please correct me if I am wrong. Other examples of ITA’s desire to produce an exceptional boat is reflected by details such as glassing the entire hull to deck joint creating an incredibly strong structure. This is very labor intensive and not something the majority of the other manufactures do. In addition, it is reflected by small details like their approach to installation of all thru hulls where the core is fully removed and added solid laminate to prevent any possibility of water penetration into the core. ITA’s approach to managing plumbing, HVAC, and electrical runs is outstanding and will go a long way towards creating happy owners that want to add equipment after taking delivery.

Many of the boats I have compared to the ITA also do some very fine things in regard to build execution. But again, in my opinion, overall the ITA is a level above the majority of boats unless you go very high end like the HH boats. In the ITA price range, I see no real comparison to the level of attention ITA pays to building an outstanding boat.

Overall Design Elements

ITA has a general philosophy to keep the decks as clean as possible. This is after all an Italian boat where key factory people have come from stylish builders such as Wally. So there is a real focus on implementing some very innovative approaches to running rigging, line handling, tank fills and vents, bow anchor, and installation of components such as the tramp. For example nearly all lines will be below deck in custom fitted runs including spinnaker guys, furling lines, reefing lines, halyards, and so on. All tank fills and vents will be centrally located in a locker forward of the main cabin. ITA’s approach to the installation of the tramp will use no exterior fastening and will be contained within a specially molded section.

ITA’s approach to the installation of the main cabin windows, main bulkhead, and support for the cabin top will provide a truly unique experience from the majority of the cats I have compared it to. The main cabin will have a wonderful openness to the exterior and provide fantastic views. ITA has elected to provide one head per hull, so a single head servicing the two guest staterooms in the port hull. This provides a wonderful roomy layout for the guest head unlike the cramped double head set up most catamarans provide. Both heads have separate stall showers with seats, yes actual seats in the shower. Despite the fact that the ITA is a performance cruiser, the hulls are surprising wide and do not feel cramped. Part of this is the result of the bridge deck design that allows for inboard cabinets to be set back and provide more space. Also, the design of the dagger board trunks keep them as far outboard as possible and they do not significantly interfere with fore and aft access. The port guest head is outboard and the dagger board trunk is accommodated between the vanity and the shower, completely out of the way. Also, very important in my evaluation is the capacity of the tankage on the boat. ITA has done a great job in tank placement to keep them centered in the boat, accessible, and with good capacity. This, in my opinion, is a real differentiator when compared to most the other boats we have looked at.

Further, based on the standard boat equipment list, it is clear that ITA is using very high quality components throughout right down to the smallest parts such as tank vents, furniture hardware, and thru hulls. The major components such as the HVAC, electrical, and plumbing systems are also very high end. Running and standing rigging is top end with great options to choose from.

Other

Not much to say here. Every Buyer will need to do their own evaluation to determine who they feel comfortable working with. For me, the bottom line is that you want to do everything possible to have a good experience when you make a major purchase like a large catamaran. You need to have confidence in the dealer and manufacturer to do the right thing and follow through on their commitments. Further, I plan to cross oceans with family and friends onboard, I want to have complete confidence in the vessel I am on and keep risk at a minimum. The whole experience of buying and commissioning your boat should be fun and not stressful. The US dealer and ITA Factory personnel have been wonderful to work with so far and extremely helpful. I believe I can rely on them to help me make the right decisions and deliver a safe platform to go sailing and have some fun doing it.

Gary

Grazie Mille Gary

[Catmandu]

Gary,

Nice writeup. Appreciate all of the thought and energy that you put into it.

I agree people that are looking for a performance cruising boat need to consider the performance when loaded for cruising. It’s not uncommon to see boats stretched after they get out on the water and owners load their stuff on board. I was told that the first time they floated the Gunboat 55 the first transom step was under water. It is now the Gunboat 57. The Outremer 49 is now the 51 and so on.

Builders tend to hide/lie about the actual weight of their boats - beware or you may be disappointed after you load your stuff on board.

480 kg/cm is impressive if it holds true and the boat should be able to take on a load and still perform. Most 50’ cats will sink 5-6” with 8,000 pounds added. This will be a differentiator if true.

the critical test is - will it sail close to windspeed loaded in 10-12 knots of true wind?

Bridge deck height is critical. (Don’t buy a cat you can’t drive the dinghy under.). Loved the Catana 471 for this … never once slammed in 6-8’ pushing the boat hard. In comparison a Lagoon 450 slammed continuously in 2’ seas on a day sail to Anegada.

Epoxy is a HUGE perhaps THE differentiator between this boat and the Outremer. I believe Balance is an all-epoxy boat.

Clean decks - critical. I loved the older 471/522, Cantanas that have no hatches in the deck. Those boats had 44mm of insulation in the decks and are much cooler boats in the tropics - really important for live-aboards and Air conditioning

One head per hull is the way to go. Better to have two luxurious heads than 4 cramped ones jammed into the living spaces … two less toilets to fix.

Questions:

Do you know if the windows are safety glass or plexiglass?

What about deck/coachroof insulation?

Is it pre-pumped and wired for air-conditioning?

Generator? I assume so

How thick are the rudder stocks? IMHO, each rudder should be WAY OVER BUILT - strong enough to slide back on a big wave or hit a sand bar at speed and not bend or break - you don’t want to end up like that first Alpha boat did out in the open ocean)

To me its seams like this boat is closer to the Balance than the Outremer. It will be interesting to compare prices of similarly equipped boats from Balance 521, Outremer 51 and this new ITA boat.

Appreciate you bird-dogging this for the rest of us.

[BigBeakie]

Correct me if I am wrong, but at 480kg/cm that is in the ballpark of a comparable length Lagoon. Thats over 2,500 pounds per inch. Pretty serious floatation.

I have closely looked at immersion rates of performance cruisers and 250 to about 350 kg/cm is more "normal" for boats with an 11:1 to 12.5:1 Lwl:Bh hull form.

Do you know the lwl:Bh of the ITA? I'll be interested to see the stern shape re parasitic drag.


Sent from my iPad using Cruisers Sailing Forum

[Catmandu]

Iliohale stated that the waterline beam is 4.95 ft making it a 10:1 L/B Ratio - kind of the going rate for performance cruising cats.

Our 55' cat had a 10:1 L/B ratio and a immersion/displacement rate of 1,780 lbs/in or 318KG/cm and as you pointed out 480 kg/cm is significantly better than most and worthy of a closer look.

So if the ITA guys really have a 10:1 L/B ratio hull that has immersion/displacement rate of 480kg/cm and can still perform then that would be a really BIG differentiator.

While its fun and interesting to compare numbers I believe that no one will really know until they put one in the water and load it up - proof is in the pudding. If the ITA boat can approach windspeed in 9-12kts of true wind all loaded up I would say they did really good.

[SVNeko]

All details about the boat reported by Gary and that I have seen on the internet look fantastic. However, the immersion figure seems too high to me. I believe it is simply a function of buoyancy and once a hull is floating on its lines, it's just a matter of the volume to be immersed. A Chris White Atlantic 48 has an immersion figure of 1524 lb/in, which I believe is approx. 272 kg/cm. How can the ITA be so much higher but still purport to have performance hulls?

[BigBeakie]

Originally Posted by SVNeko

All details about the boat reported by Gary and that I have seen on the internet look fantastic. However, the immersion figure seems too high to me. I believe it is simply a function of buoyancy and once a hull is floating on its lines, it's just a matter of the volume to be immersed. A Chris White Atlantic 48 has an immersion figure of 1524 lb/in, which I believe is approx. 272 kg/cm. How can the ITA be so much higher but still purport to have performance hulls?

Yes I agree on the immersion figure being quite high for performance cat. But if you look closely at their hull form from the tooling video, I see very flat bottoms carried way forward past "normal". That, together with the 10:1 Lwl:Bh would provide a helluva lot of bouyancy. BUT, it may come at the cost of parasitic drag which has it's highest effect at low speeds and high speeds. Also with so little rocker and such full sterns, it may pitch in short chop rather than cut through. But that is just speculation on my part, I only know the skuttlebutt of designers that do understand hydrodynamics of hull shapes.

One thing I did when choosing our cat was plot a graph of Lwl/Bh vs SA/D, and I think this is an excellent metric to get an idea of performance in BOTH light and fresh breezes. The Lwl/Bh of this boat at 10:1 and the SA/D value of 24.2 put it very close to the St Francis 50 on the chart.

I'll try and attach my chart here but no promises, it is in PNG format....

[SVNeko]

St. Francis 50? We need to revisit all these numbers and nail this down.

[BigBeakie]

Originally Posted by SVNeko

St. Francis 50? We need to revisit all these numbers and nail this down.

Data source is Multihull Dynamics database Multihull Dynamics, Inc. - Home

[Catmandu]

You have to be careful when "running numbers" as it's hard to compare apples to apples even on Multihull dynamics. The term "lightship displacement" can vary from builder to builder.

For example our 55' cat is listed as having a "displacement of 27,500 lbs" by the by the designer. In truth it weighed approximately 24,500-ish lbs empty, 25,700-ish lbs after we added air conditioning and a generator and 29,500-32,000 (as measured by the travel lift) when loaded up with our junk, spares, people, food, fuel, no water, dinghy ... etc. Note the reading on the travel-lift will vary based on where you place the straps ...

So what is the *real* "lightship" value for our boat? 25,000? 27,500? How is that defined? Does it mean weight of water displaced by boat with all gear but empty tanks? Does it include the dinghy? My experience is that it is not standard in the industry and varies from builder to builder ... they do tend to be cagy about the final weight of their products.

In any case, what mattered most was how our boat sailed with people, a months food, fuel, water, and all of our junk on board.

The most interesting info that Gary conveyed was the claimed immersion rate of the ITA 14.99. Regardless, I do believe that this is going to be a very well sorted out boat when they launch.

[BigBeakie]

Yes but Multihull Dynamics is still by far the best resource to compare designs. What else would you suggest?

The numbers are still very relevant. They may not be perfectly accurate, but we can still tell when, for example, a designer has put on a huge mast to try to compensate for fat hulls, by comparing comparable sized boats. The outliers stand out from the grouping, and then you can delve into why that is. Which is very useful to someone trying to decide on which boat is which and how they are likely to perform.

Another interesting factoid about MD that some may not realise is that 1. they are quite knowledgeable about multihull design principles, and 2. They actually discuss the design parameters with the designer to ensure as much accuracy as possible. If the designer is less than helpful, I believe they get the accurate numbers from other sources when required. I have heard this from 2 designers that they had extensive discussion with MD before their boats were included in the database.

But my point is plotting Lwl/Bh vs SA/D in Excel from MD data can be very revealing👍


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