Motoryachts Capsizing

Discussion in 'Powerboats' started by Tad, Nov 4, 2003.

  1. Tad
    Joined: Mar 2002
    Posts: 2,303
    Likes: 185, Points: 73, Legacy Rep: 2281
    Location: Flattop Islands

    Tad Boat Designer


    The boat Will posted is a completely stock 506 Motoryacht model from Carver Yachts, see it here Carver

    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.

  2. Willallison
    Joined: Oct 2001
    Posts: 3,590
    Likes: 130, Points: 0, Legacy Rep: 2369
    Location: Australia

    Willallison Senior Member

    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.....
  3. gonzo
    Joined: Aug 2002
    Posts: 14,449
    Likes: 640, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    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 :)
  4. 8knots
    Joined: Feb 2002
    Posts: 266
    Likes: 12, Points: 0, Legacy Rep: 352
    Location: Wasilla Alaska

    8knots A little on the slow side

    I stand corrected. I am just to old fashoned I guess.....I cant believe Carver makes a living selling those things.
  5. SailDesign
    Joined: Jan 2003
    Posts: 1,964
    Likes: 96, Points: 58, Legacy Rep: 650
    Location: Jamestown, RI, USA

    SailDesign Old Phart! Stay upwind..

    8knots - I can believe they make a living selling them, but I can't believe they sleep well at night afterwards......
  6. cgorton
    Joined: Aug 2003
    Posts: 50
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Massachusetts

    cgorton Junior Member

  7. Timm
    Joined: Aug 2002
    Posts: 107
    Likes: 2, Points: 0, Legacy Rep: 64
    Location: Crystal River, FL USA

    Timm Senior Member

    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.

    Attached Files:

  8. Tad
    Joined: Mar 2002
    Posts: 2,303
    Likes: 185, Points: 73, Legacy Rep: 2281
    Location: Flattop Islands

    Tad Boat Designer


    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.
  9. Guest

    Guest Guest


    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
  10. mmd
    Joined: Mar 2002
    Posts: 378
    Likes: 16, Points: 0, Legacy Rep: 309
    Location: Bridgewater NS Canada

    mmd Senior Member

  11. L.DOSSO
    Joined: May 2003
    Posts: 71
    Likes: 0, Points: 0, Legacy Rep: 9
    Location: FRANCE

    L.DOSSO Junior Member

    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.
  12. fede
    Joined: Sep 2003
    Posts: 238
    Likes: 2, Points: 0, Legacy Rep: 34
    Location: milano

    fede Senior Member

    Condo boat

    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:
  13. oddball
    Joined: Nov 2003
    Posts: 42
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: ohio

    oddball Junior Member

    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 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.
  14. gonzo
    Joined: Aug 2002
    Posts: 14,449
    Likes: 640, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

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

  15. fede
    Joined: Sep 2003
    Posts: 238
    Likes: 2, Points: 0, Legacy Rep: 34
    Location: milano

    fede Senior Member

    sorry :(
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.