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Marlow 65' seatrial vibration

Discussion in 'Marlow Yacht' started by bayoubud, Mar 8, 2017.

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  1. bayoubud

    bayoubud Senior Member

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    ob, he gave me a list, the surveyors I wanted were either booked or did not respond. The one I hired said he had surveyed three Marlow's and also recommended on another forum. I don't think he had ever set foot on one.
    Mostly a mid powerboat and sailboat surveyor. His survey was eight pages! We knew it was not going well before we were back to the dock. He did refund our money after reviewing the survey, which did not take long. lol Marlow concurred about survey results and supposedly removed him from their list.
    Last edited: Jun 23, 2017
  2. Capt Ralph

    Capt Ralph Senior Member

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    Kids in FL may remember this lil boat from the 80 & 90s. Alaura 30. Single screw, big prop, lots of HP and a big keel rite ahead of it. At speed, your teeth would grind. Factory started putting smaller engines and props on them and finally went to a new twin engine boat.
    Old Pembroke Huckins himself finally redesigned the keel and the fix. Started 3 feet forward of the wheel and cut the keel straight to the shaft. Then tapered the back edges from way ahead of the keel above and below the shaft. Experimented with some new wheels and problem was fixed. The keel was just starving the props for water.
    Shame the boat already had a bad rap and the fix was to late. Was a nice boat.
    Funny thing, it was a sail boat company that started making them, think Hunter, then finally Lhurs.
    I bring this up, I learned from this year's ago. Looks like Marlows design team screwed da pouch on showing any experience in under water design.
  3. bayoubud

    bayoubud Senior Member

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    Marmot,I agree. We were switching from SF's to pilothouse/my's and looking at boats totally unfamiliar with. Builders I know nothing about. Now, we are back looking at Made in USA SF's. Maybe an enclosed bridge sf.
  4. bayoubud

    bayoubud Senior Member

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    screwed da pouch!! LOL!!!!
  5. PacBlue

    PacBlue Senior Member

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    Did a Naval Architect even design the twin skeg hull?
  6. olderboater

    olderboater Senior Member

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    One read of all the Kakawi documents was all it took for me. The worst one might imagine, it's worse.

    In business I preferred vendors not have problems. However, the time I really found out about them was when they had issues, I saw how they handled them. Best example in history is how Tylenol handled their situation. They saved a brand that could have been destroyed.
  7. bayoubud

    bayoubud Senior Member

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    Read there was a naval architect Pat Bray in British Columbia that did some initial design work on the strut keels and Marlow has applied for copyright on the hull design with the " Velocijet Strut Keel". They make big claims as to the efficiency and how well they work. You can read about it here:
    http://www.marlowyachts.com/Velocejet_Strut_Keels.html
    plus the tunnels and etc. The line drawings on the hull shows a fairly flat bottom forward and the bow could be finer. Probably has a lot to do with comments of being a wet boat and not so good of ride by Capt's that have ran them. The bottom design I saw was fairly complicated aft, probably tricky to get the struts, tunnels, and rudders all aligned. A lot going on in that area. Their exhaust dump is farther forward than others I've seen and could be the problem with getting into the props which according to previous post cause vibrations and the stabilizer fins could even be part of that problem. All that combined could be why some had reported vibrations they could not fix.
    Last edited: Jun 23, 2017
  8. Marmot

    Marmot Senior Member

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    Cavitation, ventilation, poor workmanship and poor design and fitting of rudder bearings and linkage were found to be the main reasons for the vibration and noise issues we experienced. Efforts to build a powerful but light high speed yacht without any previous experience with larger hulls and industry standards were, in my opinion, the root cause of the physical problems.

    Refusing to even acknowledge many of the serious issues related to quality and performance as well as very serious failure to comply with class requirements in both design and construction was what lead the owner to file a lawsuit without concern for the costs.

    Poor workmanship and lack of oversight or inspection lead to workers cutting multiple structural members to install interior lighting. This was on a boat that was sold as and paid for as an IACS unrestricted ocean service yacht.

    Poor design involved coating the interior of raw water coolant piping with some kind of rubbery material that peeled off and blocked the holes in the exhaust spray ring leading to destruction of the fiberglass exhaust piping from overheating ... and very expensive repairs that the builder refused to address.

    Faulty bonding of the "swim platform" to the aft bulkhead (transom) lead to it flooding and becoming an unintended aft peak tank. But on the bright side, I guess you could say the added mass of the flooded platform helped damp the vibration to some extent.
  9. bayoubud

    bayoubud Senior Member

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    Marmot, going back to the earlier post comment on "very poor linkage fittings on the rudders". During the initial walk-thru I notice the lack of access and visibility of the rudder/steering system for inspection and maintenance., I mentioned to the broker that I did not like it and ask it the area could be modified for good access. He said I could take a saws-all to it and then later said I "probably could not fix a rudder problem if traveling anyway". I also noticed a port trim tab leaking fluid and mentioned it to him and he said would have fixed. Well, our sea trial bombed out because not being fixed and that trim tab stuck in the down position during the sea trial. No excuse for how our situation turned out. Sounds like your owner was already in the boat before discovering all the problems.
  10. Capt Ralph

    Capt Ralph Senior Member

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    http://www.marlowyachts.com/Velocejet_Strut_Keels.html

    Those pocket (prop tunnels?) in the hull look short (fore/aft) in front of the propeller. Inviting for capturing air and expanding exhaust that may never clear.
    I'm learning a lot here. Hope you don't mind my comments.

    THX
  11. bayoubud

    bayoubud Senior Member

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    rcrapps, same for me. There have been some educational post on this thread. My last boat a hatteras sf had tunnels and never an issue. I would not know a good tunnel from a bad one. The Marlow tunnels are fairly deep and have the strut keels mounted center from the front in the tunnel. Also has underwater exhaust forward and outboard which I think can get into the tunnel. You picked up on that too. Your comments are always welcome.
  12. Capt J

    Capt J Senior Member

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    I ran a brand new 56' in very moderate seas a few years back. While running at 16 knots cruise with the wesmar digital stabilizers on. It was 2-4' off of our starboard beam, it pitched to the port side once so violently a 12 can cooler flew across the flybridge from the starboard side to the port without ever touching the ground. It scared the living daylights out of me it pitched over so far and fast in a moderate sea state......the running gear would also chatter at times with cavitation induced vibration. Also on the 56's and 65's while at anchor or docked if a 10" wake hits the sqim platform it vibrates/resonates pretty noticeably throughout the entire boat. POS.
  13. bayoubud

    bayoubud Senior Member

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    Capt J, the 65 we sea trialed had the old bolt on platform, did not like it. As far as the ride, we never got out of sight of their facility in flat water, so I can't comment on that. We did run over our wake though. Marlow seems to have plenty of criticism about the ride from experienced Capt's like you. They do tout their brand but have not seen other builders copying the designs features.
  14. PacBlue

    PacBlue Senior Member

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    Thanks for the read, although I have to say the Marlow article covered the topic in a very difficult to follow manner, traversing territory all the way to twin fin supersonic fighter jets as proof of concept. Seemed like more fluff than real stuff, but lead me to ask myself, who would hold the patent on the Velocijet Strut keel, Marlow or Bray? Why would a NA turn over his Intellectual property (IP) for no gain, if it was indeed his design? Somehow, I am led to believe there is more to the Marlow Twin Keel story.
  15. bayoubud

    bayoubud Senior Member

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    PacBlue, maybe they copyrighted the name only. A lot of it is marketing hype, like they are the only ones offering this hi-tech design. Seems the designer would get some type compensation.

    Just stumbled up on this boat with twin strut keels, but without tunnels.

    [​IMG]

    [​IMG]
  16. Capt Ralph

    Capt Ralph Senior Member

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    Now that looks simple and sweet. Thin steel (alloy?) keels, wheels are deep and away from the hull.
    Not sure what trim effect the hotz rudder plates offer but may be there to act as an anti-vent plate while backing hard.

    Is that Cable (West) marine in the background?
  17. bayoubud

    bayoubud Senior Member

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    What I thought rcrapps, simple and sweet... It is a 57' steel trawler located in Lauderdale listed on YW. A custom build for blue water cruising. What is the purpose of the hotz rudder plates? Notice she is blocked up on the keels.
  18. Kapn

    Kapn Member

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    I'm not a naval architect, but I have spent a lot of time in a boatyard. Those props are pretty small. Must be lower hp engines and displacement speeds. That may be different than the 20+ knots the Marlows attempt to achieve.
  19. bayoubud

    bayoubud Senior Member

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    I agree 100%, when you add speed, tunnels, and underwater exhaust like a Marlow, it gets complicated. The boat in the pics is a trawler.
  20. Capt Ralph

    Capt Ralph Senior Member

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    I think larger wheels and more HP could still work on these thin keels.