Bridge Deck Clearance ? How Much 40-50ft !

[Jimbo485]

Yeah, yeah, get out of the armchair!

You want windage, pointing ability, speed or leeway? Or some magic?

Answer the question ONLY after you have done sufficient research / experienced it while in the cockpit / bashed to windward and screamed downwind for a few hundred miles / etc......

[cruiz9]

I own a Schionning Wilderness 1620 ,thats 53ft, we have sailed 15,000 ocean miles in some pretty attrocious conditions and the only time we ever slammed under the bridge deck was a crossing of the Gulf of Carpentaria in northern Australia,a notorius area for very short confused seas. Even then it only happened on a handfull of occaissions ,so didnt bother us at all. The bridge deck clearance is around 1mtr loaded for cruising . I have heard of some production cat owners who just accept bridge deck slamming as a fact of life, fact is it can be structurely dangerous and damn right scarey and very noisey to have a low bridge deck.
I have attached a link to a video of my boat taken bow on where you can see the clearance and how the boat behaves while sailing Albiet in slight conditions.http://<iframe width="560" height="315" src="http://<iframe width="560" height="3...reen></iframe>" frameborder="0" allowfullscreen></iframe>

[Mark Johnson]

Barry,
You make good points about the problems with production cats. Having built, sailed, and followed multihulls for 40 + years now, I can say that, "back in the day", when most folks built there own, "most" were built to better designs.

They had much better wing clearance, good leeway prevention, lower cabin height, smaller cabins with wider side decks, lower COG and lower windage, higher headsails that you could see around from the helm, lighter build weight per foot, and better performance. WHY? The guy who built his own boat, wanted a real "sea boat"!

"Production" boat designers and builders are not in it to design/build the best boat. They're in it to make a living. ACCOMMODATIONS SELL BOATS for the cruising set... BLINDING SPEED SELLS BOATS, for the racing set. That means one of the two extremes sell, like very small accommodation rockets that cost a fortune for what you get, OR CONDOMARANS, that excel as a dockside party boat, but fall short as a true sea boat.

There are one or two exceptions out there, but for the most part, the best cats out there are custom one offs, from decades ago. IMO... They were just built to a better design.

Mark

[bob_77903]

800mm sure sounds better than 31.5 inches...

[TOM]

We do not own a cat but perhaps one day would like to. I'm confused if BDC is so importent how come we see all these low BDC CATS crossing oceans . We met a family of 4 who took a 38 foot Prout around the world via Patagonia ,the bdc was so low it almost touched the water! . We have friends on a 48ft Mayotte with ridiculously low BDC who have sailed all the way from Thailand to Brazil crossing 2 oceans with no problems, part of that trip was from chagos to Rodrigues with swell on the top quarter. There are literally hundreds of low BDC cats circumnavagating and crossing oceans BANGING and SLAPPING there way aroud the globe So please can someone explain to me what the big deal about BDC IS !!

[cruiz9]

Try doing a belly flop from 5ft and see how that feels on your body ,you would not like it and neither does a boat ,the reason you see a lot of LBD boats crossing the oceans are because most of them are badly designed production boats primarily designed for the charter market in protected waters.Unfortunately people are forced into these boats because of budjet restrictions. Just because you think everybody does it doesn't make it right.

[Richard5]

Mark Johnson, great post!

Tom, a peculiar nature of humans is they are very accomodating. Perhaps they get used to hull slaps and rapid deceleration in a head sea but it isn't ideal. Or perhaps they trade speed or pointing to windward for comfort. To say a slappy boat does make a passage is to say nothing of how swift that passage.

[Sand crab]

Originally Posted by Cheechako

On my Lagoon 42 I could barely take the 10ft RIB with 15hp Yamaha under the boat with 2 people in the dingy. It seldom pounded. Sorry dont know how much clearance that is , but more than many of the boats I see advertised.... anyone know what the TPI 42 cleanace was?

55cm at lowest point. Look here.

http://www.cruisersforum.com/forums/...2-a-59922.html

[FLLCatsailor]

Dont you buy a catamaran to sail off the wind??? I agree with Tom... Too many people obsess with BDC...

What do I know... I've only delivered dozens of different production cats in all kinds of weather...

[Factor]

If you think BDC isnt important, well I dont really know what to say. Its not just speed or comfort its about reliability and failure and the ability to actually make way in bad weather. Even your company worked that out and got some designers (morelli and Melvin) in to get more than a couple of inches into the BDC.

[bazcatana]

Originally Posted by Richard5

Barry, you have ETA for launch of website? Thanks.

Hi Richards5 and other Forum members,

I have to watch what I say in the Forum because I seem to cross the line, I want to help Cat owners and potential buyers to buy the best Multihull for the right reasons.

There are too many Condos, Caravans with masts, and Cats that seem to brake the rules, one minute we are told you can't have a tall Mast because of Capsize, then the designers tell us we want Fly Bridges that raises the Center of effort which causes Capsize.

Watching the guys with Fly Bridges who cannot reach the Mainsail because the Boom is 6' above their head. One guy used a step ladder to climb up, he is 14' off the water on a step ladder - Health & Safety went out the window.

ETA on what you asked about is 14 days hopefully.

Regards

Barry Parkinson

[cruiz9]

My boat is a Schionning Wilderness 1620 ,53ft, with around 1mtr of clearance. We have sailed around 15,000 ocean miles ,some in attrocious conditions and the only time we ever got bridge deck slamming was in the Gulf of Carpentaria in northern Australia, which is notorious for short steep confused seas,it only happened a few times so didnt worry us to much,but its certainly not something i would want happening all the time. I have attached a video of my boat filmed bow on showing bridge deck clearance when sailing albeit in slight seas

http://www.youtube.com/embed/MA1Ta03VQXA

[courju]

Originally Posted by Mark Johnson

Barry,
You make good points about the problems with production cats. Having built, sailed, and followed multihulls for 40 + years now, I can say that, "back in the day", when most folks built there own, "most" were built to better designs.

They had much better wing clearance, good leeway prevention, lower cabin height, smaller cabins with wider side decks, lower COG and lower windage, higher headsails that you could see around from the helm, lighter build weight per foot, and better performance. WHY? The guy who built his own boat, wanted a real "sea boat"!

"Production" boat designers and builders are not in it to design/build the best boat. They're in it to make a living. ACCOMMODATIONS SELL BOATS for the cruising set... BLINDING SPEED SELLS BOATS, for the racing set. That means one of the two extremes sell, like very small accommodation rockets that cost a fortune for what you get, OR CONDOMARANS, that excel as a dockside party boat, but fall short as a true sea boat.

There are one or two exceptions out there, but for the most part, the best cats out there are custom one offs, from decades ago. IMO... They were just built to a better design.

Mark

Hello Mark,

I think you are taking shortcuts without taking into account the usage of the boat.
A 20 years old sailer will not look at the same boat than a family with 2-3 children. And for a retired couple it will be a different vision too.
Just keep in mind than most of the production is staying in the marina and will never do more than a 100 miles run...
However, a circumnav family will want a minimum comfort in order to make sure kids enjoy this life: in this case what you call a 'production' boat is a great boat.
But if you are single most probably you will prefer a boat built in India or Thailand: she will have very good performance but will never be a 'friendly' boat for a family.
Comparing a Porsche with a Volvo is a non-sense... A sport car and a motorhome have different usages

Cheers

[courju]

Originally Posted by bazcatana

Hi Richards5 and other Forum members,

I have to watch what I say in the Forum because I seem to cross the line, I want to help Cat owners and potential buyers to buy the best Multihull for the right reasons.

There are too many Condos, Caravans with masts, and Cats that seem to brake the rules, one minute we are told you can't have a tall Mast because of Capsize, then the designers tell us we want Fly Bridges that raises the Center of effort which causes Capsize.

Watching the guys with Fly Bridges who cannot reach the Mainsail because the Boom is 6' above their head. One guy used a step ladder to climb up, he is 14' off the water on a step ladder - Health & Safety went out the window.

ETA on what you asked about is 14 days hopefully.

Regards

Barry Parkinson

Hello Barry,

Fly Bridge or not is not a question of safety: it is a question of feeling. You like or you hate (there are already a lot of topics about it...) but keep in mind that the architect of these boats (I think you are mainly targeting French builders) are also the ones who designs the fatest multi of last decades... They know what they do.
Waiting your website to be online to see what is a good cata for you...

Cheers

[dirkdig]

Fly bridge's are the best