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Aggressive Yaw/Roll on Ocean 66SS with following seas

Discussion in 'Ocean Yacht' started by SMR-PILOT, Feb 1, 2015.

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  1. Capt J

    Capt J Senior Member

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    Well, keeping some fuel in the fuel tanks would help immensly.....as would filling the livewell and cockpit fishboxes with water.........
  2. saltysenior

    saltysenior Senior Member

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    we added about 2 1/2 '' to the bottom of each rudder on a 40' SF years ago....made it a different boat. Stupid me spent the whole weekend dropping the rudders and bringing them to the yard's shop...Mon. AM ,the welder (brazer) say's he could have done the job w/ the rudders in place ...
  3. docjr03

    docjr03 New Member

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    What helped you determine how much to add?
  4. SMR-PILOT

    SMR-PILOT Member

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    I don't fill the tanks all the way because of some leaking at higher levels. I gotta get that fixed. I'll try adding some weight on the stern this weekend to se how she behaves.
  5. NEO56

    NEO56 Member

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    I really hate to point out the obvious here to the OP, but why in God's name did you not sea trial the boat before buying it? Could have saved you a lot of time and aggravation....and buyers remorse. Personally, I won't sea trial a boat in anything less than 6 to 8 foot seas. Just about any boat will run good in a 1-2 foot chop.
  6. Capt J

    Capt J Senior Member

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    Fill the fishboxes and livewell with saltwater......see how she behaves.....
  7. Capt Ralph

    Capt Ralph Senior Member

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    Of course Skippy J forgot the ice and beer. If your gonna bunker da boxes....
  8. Capt Ralph

    Capt Ralph Senior Member

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    Then just fill the after tank. You have some toys on the fore deck a'lil beyond design specs you have to help balance out.
  9. Capt J

    Capt J Senior Member

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    If he can't afford fuel, how's he going to afford beer and ice? hehehehe;)
  10. Pascal

    Pascal Senior Member

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    Too much weight at the bow is compromise you have to accept if you want to carry toys although having both a jet ski and a tender seem a bit too much on the bow of a boat that size,

    I m not sure why you d want to carry so little fuel in your tanks, you re compromising handling just to gain maybe a knot of cruise speed, makes no sense. Starts by running with full tank and see how it goes.

    I run a 70' johnson skylounge which is pretty top heavy as we have the jet ski and tender up top along with an enclosed flybridge. I pick my days :) anything over 3' on the quarters and the autopilot is useless. Between 3 and 5' I can smooth out the ride with a lot of steering input, over 5' I change course or stay put.
  11. saltysenior

    saltysenior Senior Member

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    I don't remember, but it was agreed by all that more rudder blade deeper in the prop wash would help...It made quite a change to the better.
  12. SMR-PILOT

    SMR-PILOT Member

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    I don`t carry a lot of fuel because of leaks in the tanks at higher levels. I know that carrying those toys on the bow might be a bit too much, but having them when you`re at a remote beach makes all the difference in how much fun you can have. I`ll just add more weight on the stern and that should help with the issue....

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    Last edited by a moderator: Feb 4, 2015
  13. SMR-PILOT

    SMR-PILOT Member

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    I did trial it. I think the problem has more to do with the fact that I added some toys on the foredeck plus I can`t fill the fuel tanks very much because of leaks. I posted this thread mostly to get a little insight on sport fish boats, which I`m new to. P.S. I got this boat for REAL cheap and the engines are great, so overall it was a great buy from my perspective.
  14. YachtForums

    YachtForums Administrator

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    SMR-Pilot,

    Please check your image size before uploading to YF. 640 pixels is our max. That pics was 1200. I have reduced it.
  15. Beau

    Beau Senior Member

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    Wow look at that water line. Seems he is using a lot of the bow's buoyancy already, so he really must "plow" with a following sea. Take the stuff off the bow and go for a sea trial ?
  16. Capt Ralph

    Capt Ralph Senior Member

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    Let me make sure I'm reading this correctly.
    Purchased the boat with leaking fuel tanks. Added the stuff forward and did not fix the tanks?
    AND, nobody noticed the ships trim change significantly dockside?
    That is a beautiful looking ship though.
  17. docjr03

    docjr03 New Member

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    He has another thread going discussing the fuel tank issues.
  18. SMR-PILOT

    SMR-PILOT Member

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    thanks. Replacing the tanks is not an easy job. Will probably do it on next dry dock in about a year. For the moment, I can do with the small leaks. Somedy else has a Thread about this issue with the tanks on ocean yachts, so I guess it's a common problem. That pic was taken with very little fuel or weight on the stern. She usually isn't down by the head like that. Like I said, I'm aware of the weight distribution issue, I was more interested in getting some insight from people with experience with ocean boats and SF boats in general, so I could determine how much of the yawing issue was due tu hull design rather than weight distribution. I have already added more weight on the stern and will be trialing the boat soon.
  19. Beau

    Beau Senior Member

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    I was more interested in getting some insight from people with experience with ocean boats and SF boats in general, so I could determine how much of the yawing issue was due tu hull design

    No experience with Oceans. My 30 ton Post 50 does just fine in following seas, but I run ahead of them, if they are to big for me to do that I stay home. The earlier Post 42 and 46 were squirrely in a following, but there were some design changes that fixed that. Maybe someone else knows what they were. That SS40 increased his rudder size? Good luck. Good looking vessel.
  20. Capt J

    Capt J Senior Member

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    Pascal= try adjusting the sensitivity in your autopilot as it should steer better than you in 3-5' seas. It will be labeled response or sensitivity or something along those lines, depending on the brand of autopilot you have. But I generally adjust it on a delivery maybe once or twice a day depending on fuel load and sea state. But dialing it up should make the autopilot respond and steer faster, but you may have to dial it back down in a calm sea state.....it's a few button clicks though.

    SMR- Your boat is very bow heavy from the pic. Honestly, when you do your fuel tanks, I would replace them with exactly what is in there, not the hokey 3 fuel tanks plumbed together that you were planning, even though it is quite a lot of work to do that. I would say about 40-50% is the boat design. The rest is the weight distribution due to the low fuel, dinghies and etc. To help short term you can fill the livewell and fishboxes with saltwater from the washdown pump, or even just to go on a sea-trial and try it, Also if you want to rule everything you've added from the equation, dump the toys in the water and seatrial the boat with fishboxes full of water and no toys on the bow and you'll know what your baseline is. Motoryachts due this also if you screw up the trim too much.