Motoryachts Capsizing

[Tad]

Can anyone report a case of a modern motoryacht (of reasonable size) capsizing? I know the USCG has done it on the Columbia River Bar. It happens occasionally to high-speed boats, usually when they are airborne.

Steve Dashew has made a claim that "99% of all powerboats" are unsafe. I think he is wrong. See his column

here (http://www.setsail.com/dashew/dashew215.html)

Thanks, Tad

[SailDesign]

I think you're taking him slightly out of context, Tad. He says that "The powerboat industry must assume that there are no capsize risks, because as far as we can see, 99% of all powerboats--right up to 100,000-ton bulk ore carriers--will capsize and not recover, given the right set of circumstances. "

That implies a set of circumstances that are very hard to achieve, and almost says "if you put sails on a powerboat, it will be unsafe", or at least that's the way I read it. Yes, any powerboat can capsize and not recover, given sufficient heeling moment. Currently the only way you are going to apply that moment is by steaming side-on to a hurricane, or being broadside to a large breaking wave.
By the lights of his sentence above, he is right. But it sure sounds like a spin to me....

Steve

[Willallison]

But it sure sounds like a spin to me....

...and to me.....
then again - I would reckon that he's not far off the mark. You only need to take a wander down to your local marina to see that VERY few powerboats would recover from a capsize. What he's failed to mention, however, is that 99.9999 % will never venture far enough for it to become a problem

[SailDesign]

Will,
The problem is that what he neglects to say is that there is no reason fora powerboat to be built to come back up, since the problem of rolling one can be so large. (Note the "Can" ...)
This gives the impression that stinkpot designers have been deluding and misleading the public for years, hence my reference to "spin".
Steve

[Willallison]

Yes - I understood your point Steve - and I agree. My point was simply that whilst there are more and more boats appearing that look like they'd fall over if you gave them a shove (pic below - surely a case in point!:eek: ) very few people are ever likely - nor do they ever intend - to cruise offshore, let alone across oceans - so ultimate stability isn't of such enormous concern.

To answer Tads question - I've certainly not read of any pleasure craft capsizing in recent times. You get the occaisional grossly overloaded ferry in 3rd world countries, but that seems to be about it....

[SailDesign]

AARRRGGGHHHHH!!!!!!! My eyes!!!

Thanks, Will - it's always nice to have a reminder of what not to draw. ;-)
I especially love the "radar arch" on the roof. (Yes, there is a more nautical term for it, but that boat doesn't deserve it)
Steve "hope nobody here designed that, or I'm in trouble..."

[BrettM]

If you look closely you can see at least three boats that have been cut up and stuck together to make one smaller ahem boat.

[Tad]

Steve;

You may be correct and I'm just putting my own spin on Mr. Dashew's words. But I took great umbrage at being told I don't care about stability. And Mr. Dashew has no body of research to back up his claim. How does he know that 99% of powerboats will capsize and not recover. In many cases, if the deckhouse remained intact, they would pop back upright like a cork. They would in fact be very unstable upside down. Well, that's making an assumption, but in some cases it will be true. I'm thinking of boats with big deckhouses and small windows, the British Nelson's, Nordhavn's, etc.

But besides that I am trying to ascertain the risk factor, is it one in 100, or one in 10,000, or one in a million? Were are all the motoryachts that have "capsized and everyone died"? In Heavy Weather Sailing (4th ed) Peter Hayward talks about being rolled to 90 degrees or so, but the boat popped back upright.


Thanks for your comments, Tad

[duluthboats]

Will you have to tell us the whole story, what's the beam on that baby? LOL!

Most of the boats that I know of that went down around here have run into sonething. That is the the real hazard.

Gary :D

[Guest]

Tad,

Many of the current popular cabin cruisers certainly look like they could go over fairly easily, but that is no proof that they will.

I do remember quite a few lawsuits mentioned in the Boat US monthly publication a few years ago about his very thing. There were instances of boats capsizing in fairly common circumstances especially when several crew were on the flying bridge during a routine turn. Boat US probably has records about this kind of thing.

Tom Lathrop

[gonzo]

I agree with willallison that most powerboats are fair weather boats only. They also have more speed than a sailboat so can make it into port faster. In rough weather most of those tubs will sink, I have no doubt.

[BVI Jon]

Morning,

Having dealt with at least 30-40 power boat capsizes, both in the USCG ond out, I cannot remember a single one that wasn't caused by either a shift in cargo (people, dope, food, whatever),

or

enough water entering the vessel from heavy weather, busted hose, etc to set-up "free surface effect", reducing stability enough to lay her over on her side.

Occasionally they were recoverable, but only if no more water was allowed in, and either the existing water pumped-out, or shifted weight moved back to original side.

Sorry about no specifics.

Jon.

[gonzo]

Tad:
There are many seaworthy powerboats being built. The trend in trawler yachts and converted lobster boats shows that many owners are concerned about seaworthiness. However, the floating condominium willalison posted is a prime example of a fair weather only boat. What do you mean of "reasonable size". If you referr to large yachts, it is a different story. The midsize designs are probably the worse.

[Tad]

Thank you everyone for your comments.



Tom; I will get a inquiry off to Boat US today, many thanks for that link.

BVI; Thanks for your note, the USCG (CCG as well) might have some statistics on this somewhere. I will inquire. Capsize is quite common in the commercial fleet, fishing vessels especially. But in those cases it is (almost always) caused by a combination of overloading and water getting into the vessel because of the overloading. I know of some cases of swamping, where a wave or waves come over the transom and fill the boat.

gonzo; What I am specicifly looking for is cases of motoryachts or powerboats, say between 20' and 70', capsizing due to heavy weather. There must be some cases of this happening due to power loss or just bad management.

Tad

[8knots]

I don't know of the article you all are talking about but the pic Will posted lookes like a production boat with a LOT of custom work done to it (enclosed bridge and aft enclosure) The owner got sold up the river on that one I think. He and the wife wanted to much creature comforts that could be offered in that boats available space. Looks like they went to an unscrupulus refit yard and said "We want....... here is a check" I hope they are truly coastal cruisers!
As I have wandered the docks in Alaska I see many many boats with homebrew enclosure type things on both commercial and family style boats that make me shudder to think of whats gonna happen to that THING in a blow! Alaska will kill you quick on a good day. Let alone the family bayliner running the 55nm's to Prince William sound.
If you had numbers on capsizes... It would be interesting to break them up by 1(stock boat) 2(modified) and see what happens.
anyway just a thought 8Knots

[Tad]

8;

The boat Will posted is a completely stock 506 Motoryacht model from Carver Yachts, see it here Carver (http://carveryachts.com)

Length is around 50', beam 15'4", vertical clearance 20'!!!!, displacement supposed to be about 48,000 pounds? These boats are selling like hotcakes, the builder recently announced they were looking for 200 people to expand all shifts. They are protected water boats that sell well in the Midwest where there isn't much water. They are excellent "Marina Cruisers". The company PR blurbs do not even mention that this thing is a boat, only that it has enormous interior space. I might guess the VCG would be about at the sheer level, but I guess that doesn't matter.

I did find a description of a Krogan 48 being rolled to what the owner described as 45-50 degrees. It's in Passagemaker Magazine No 2, summer 1996. There are no further stories of this type in Passagemaker since then? Who knows why.

I continue to pursue this subject, my best to all.

Tad

[Willallison]

You beat me to it Tad - and Carver are certainly not alone in offering floating penthouse apartments.

You may also have suggested your own possible lead to the question of capsize stories - contacting Passagemaker might be a good start.....

[gonzo]

The old Carvers were good running boats. I was impressed by how soft a ride they had even in a chop. Oh well Tad, not everything that floats is a boat :)

[8knots]

I stand corrected. I am just to old fashoned I guess.....I cant believe Carver makes a living selling those things.
8Knots

[SailDesign]

8knots - I can believe they make a living selling them, but I can't believe they sleep well at night afterwards......

[cgorton]

The pictured boat is a Carver 506- right off the website:

http://www.carveryachts.com/handler.cfm?thefile=models_detail&modelid=4

[Timm]

I hate to say it, but I had a very small part in the design of this hideous monster from Carver. The main part of the design was from a friend of mine (who shall remain nameless for his own protection). The hull was based on one I designed while at Carver a decade or so ago. Originally it was for a pilothouse cruiser style boat about 40' long. The original design was never built, but it was far better looking than the floating penthouse. We used to get pretty disgusted in the engineering department when the sales guys would say they were selling floating condo's. It made us wonder why we bothered to put engines in them! The attached drawing is what the original boat was going to look like. Alas, it was never built, but the hull survived with some modifications.

The only roll-overs I have seen in powerboats are usually either fishboats as stated earlier or small sportfishing boats. Usually the scenario is that a couple guys will take their 15' boat for an offshore fishing trip, get swamped by a large wave and then the boat rolls over. The boat usually stays afloat due to the flotation foam in the hull. I always find it humorous that the sailboaters worry so much about powerboats capsizing, when the boats that capsize and get knocked down the most are sailboats. Frankly, I feel much safer on a boat type with almost no history of rolling over rather than one in which stories (usually heroic stories of survival) are printed nearly monthly in magazines!

Tad, please share your findings with us as I too would like to know more about the types of boats capsizing and why.

[Tad]

Timm;

Thanks for your thoughts, much appreciated. IMO that's not a bad looking boat, it is frustrating to have your work "mauled" by the marketing guys.

My findings; so far, not much, but interesting going. I have hopes that I can actually learn something if I don't get sidetracked.

Boat US have some published statistics on their site, they examined insurance claims regarding 50 sinkings while underway of boats up to a 54' sailing vessel. (no info on how many were sail vs. power) Of the 50 sinkings, 15 or about 30% (the largest group) were caused by swamping (or, "water coming over gunwales"). The rest were because water got in some other way, i.e.: 6% sank because they came off a wave and the hull split open!!!

Of the 15 boats that sank due to swamping, 13 were outboard powered and flooded by waves coming over the transom. One of the two remaining was a powerboat "with very low freeboard" that took a wave over the bow. The last one was a sailboat that was knocked down and flooded through a cockpit hatch.

In these 50 sinkings there were no fatalities. No capsizes due to weather either.

I spent some time reading USCG accident reports. I found a capsize of a small fishing vessel, 22', by waves over the stern while being towed. I also found a fairly horrific capsize of a party fishing boat while crossing a west coast river bar. The boat was 47', and had 23 school children and seven adults aboard. They were going whale watching. Bar conditions were not considered severe, the boat stopped and observed conditions before crossing.

They hit a series of three breaking waves, the first one came over the bow and washed out the foreword windows, cleaning out the wheelhouse. Operator lost control, the boat turned partly sideways to the second wave which partly filled the cockpit. The boat was stopped and sideways to the third wave which rolled her completely, she remained capsized.

At the time (mid 80's?) it was standard practice for the CG to escort boats over the bar, there was a small RIB alongside them, they stated pulling people out of the water immediately, put one load ashore, and picked up another. The capsize was also observed from the CG base inside the river and they had another RIB on the scene in minutes. There were no fatalities.

In his book, Seaworthiness The Forgotten Factor, CA Marchaj states that capsize is "essentially a contest between wave impact, which tends to roll the boat, and inertia, which tends to resist the roll-over". There is much to study yet.

My best to all, Tad.

[Guest]

Tad,

I suspect the data on sinkings due to water entering over the stern in outboards is far too small due to under reporting. I know of two sinkings (one took place at the dock) and one swamping (following wave when power was cut abruptly) in my town on the ICW. The problem seems to be related to the need to get the prop low enough on deep V boats which drastically lowers the transom cutout.

Several years ago, I was running a regional Etchells regatta with a Boston Whaler 23' Outrage as the committee boat. While anchored, waves started coming over the bow. We moved further aft whereupon water came in over the transom and we were quickly ankle deep. None of the sailors complained when we cancelled the race for the day. Recessed wells in the sole were also flooded with no way to empty them and there were no transom scuppers either. In spite of BW's ads that these things are not sinkable, it did not handle very well.

I wrote to BW and they replied that there had been an accessory false transom to be installed in front of the low one and also accessory scuppers. These are accessories???!!! In addition, these item were no longer available. Boston Whaler get low marks from me in addition to being rough riding boats in rough water.

Tom Lathrop
Oriental, NC

[mmd]

Tad, if you haven't already found this, check out http://www.qc.dfo-mpo.gc.ca/gcc/en/statistiques1999/Plaisance.htm

[L.DOSSO]

the picture shown above is like monospace (wagon) cars which have a greatsuccess nowadays.I think why not doing a craft so high?Provided the veranda,bow window imean this ugly additional supercabin be built really light.I would like someone who is very skilled in carbon and kevlar design tells me:Yes you can built this extra superstructure without altering or increase the heel angle in turns of small radii(yawing). LUCAS
note that I registered a second time under lucas dosso name.This is not a knew member.sysop,please delete L.DOSSO.

[fede]

I guess it's more appropriate condom boat... :D
Man that Carver thing is unwatchable, and they do import Nuvari yachts ...can't they see the difference??? :confused:

[oddball]

I am new to boating but that carver 506 from the first moment I laid eyes on it looked scarey, looks like a good gust of wind might put that thing on its side, the scariest thing to ever happen to me had nothing todo with weather...but with CC ,My friends and I were on a 16 foot boat watching fireworks, when we saw a "cigerette" boat coming at us..full throtle..it got closer and closer...and cut a hard turn about 10 feet from us...the wake almost threw us all out of the boat, the clown pulled up next to us where I could see the 3/4 empty bottle of CANDIAN CLUB sitting on his dash and he said (slurring) "sorry guys...just F***ing with you" and then he drove off.... in hein site I should have snatched him out of his seat and beating the pulp out of him, I am no expert but i f you cant talk without slurring then drop the bottle AND your anchor...*****'s scare me more than weather.

[gonzo]

There is a large market for those boats. I think a safety standard would be good.
fede: please keep it polite.

[fede]

sorry :(

[tonyvv]

That Carver is one ugly boat on the outside. Looks like it was designed by a commitee of people trying sell more fiberglass. It looks pretty inside. All in all, a nice boat to cruise the ICW if you have no clue until it breaks and you have throw it away.