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Using bow thruster to steer while underway

Discussion in 'General Yachting Discussion' started by motoryachtlover, Feb 1, 2023.

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  1. motoryachtlover

    motoryachtlover Senior Member

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    this is a video of a Nordhavn (I believe) running a cut in a following sea in the exumas. In the video he is using a lot of bow thruster to keep it on course. I assume the bow thruster is hydraulic. I have a planing boat so have the luxury of enough power to aid in steering. My question to the forum is: Is that acceptable practice to use the bow thruster in this way, & is this typical for a trawler in a following sea? I thought a large rudder and keel would help with this situation. He is rolling a lot as well. Maybe the stabilizers are out of commission.
  2. Pascal

    Pascal Senior Member

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    Something is definitely wrong with this picture. Looks like Dothan Cut, south of Staniel which is a very safe and easy cut even with the current running against the wind. conditions don’t even look bad at all.

    He s using a lot of steering so obviously he has steering. He has hydraulics since the thruster is working so the stabs should be up as well

    weird.
  3. Ken Bracewell

    Ken Bracewell Senior Member

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    Are we sure that's not just someone making frozen blender drinks in the galley for the beautiful beach they're approaching?
  4. Pascal

    Pascal Senior Member

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    That would be enough frozen drinks for small cruise ship :)
  5. DOCKMASTER

    DOCKMASTER Senior Member

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    You hate second guessing someone without having all the relevant info but sure looks to me like he's oversteering and making it harder than needs to be.

    The only time I use my BT for steering is an occasional bump when trolling at slow speeds and if higher winds are pushing my bow off course. And by slow I mean on trolling valves doing 2 kts or less.
  6. JWY

    JWY Senior Member

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    I frequently see owners use a technique that I call "drive by thrusters." They are usually rather new to boating and are probably the same ones that can't find their way from paper charts should they lose their electronics. When builders started putting stern thrusters as standard equipment, it encouraged the "easy" way to maneuver rather than the "proper" way. And if a yachtsman needs to use thrusters in open water, wait til you see them try to dock.
  7. motoryachtlover

    motoryachtlover Senior Member

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    Judy do you find his rolling excessive and is this typical handling for a trawler? I am contemplating my next boat and thought a stabilized boat would not roll like that in that sea state. I do realize that videos and pictures don’t capture how rough the sea actually is. My wife would not be happy with that rolling and neither would I.
  8. JWY

    JWY Senior Member

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    I have my favorites in the Nordhavn lines, but I hold a bit of a prejudice against the hulls that have been stretched. The N63 started as the N 55 then grew to 60 and ultimately a 63. No, the running gear was not stretched also.

    Carl asked me to write a YF review on the 63 when hull #1 was cruising Florida. I had not been aboard the 63 and I had no knowledge of her, so I agreed and spent a lovely day onboard learning the boat. I have great respect for Nordhavn's success and was proud to write the review. However, I realized I was walking a fine line in upholding Carl's and my standards for honest reviews. If there are too many negatives, then we just don't write the review. And the N63 did not fall into that category as there were many good things to say about the 63, but if you read between the lines, you can find my criticisms.

    https://www.yachtforums.com/review/nordhavn-yachts-63-expedition-trawler.18344/

    Whew, long answer to your question, but hell no a trawler shouldn't roll like that and especially in those conditions as they appear in the video.
    motoryachtlover likes this.
  9. Capt Ralph

    Capt Ralph Senior Member

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    Something is wrong here.
    Was he idling thru there?
    Was it shallow and the bow was getting sucked down?
    Stabilizers set to free? or just off? The following waves catching them?
    Way to much stuff upstairs?
  10. Norseman

    Norseman Senior Member

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    Yes, something is not right..
    Too slow boat speed for normal steering..?
    They lost control of the rudder?
    Running on 1 engine on a twin engine boat?
    (A bow thruster is an excellent back-up if you loose normal steering of the vessel, otherwise docking and emergency only)
  11. Capt Ralph

    Capt Ralph Senior Member

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    Another observation;
    Thruster running, wheel turned both directions.

    One thing I learned long ago. Some APs can not do inlets on a following sea.
    Was this guy baffled? No idea or clue? Was the AP running and just to slow over all to work correctly and this guy was adding to the issue?
    What's with the rolls on a nice day??

    Re-read post # 9
    I really don't want to go hard against the guy in the video,, yet.
    Any way to ask him Whisky Tango Foxtrot??

    BTW
    I've done better with one of two down coming in the StJohns with shift on my stern.
    We don't need no stinking thruster....:confused::confused:
  12. Pascal

    Pascal Senior Member

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    There is another video on that same YouTube channel showing underwater footage. It s a single engine boat with a BIG rudder.

    Like most cuts in the exumas, Dotham is pretty deep so That wasn’t a factor. Neither was the APnas he his clearly hand steering. Personally I never run a cut on AP.
  13. Capt Ralph

    Capt Ralph Senior Member

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    Then he may had just be over cautions and running to slow,, way to slow?
  14. Capt J

    Capt J Senior Member

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    Using a bow thruster while underway is a great way to break a sheer pin or spin the hub on the plastic propped bow thrusters.

    Guys, this is how A LOT of Asian boats handle when going through cuts with current and wind. "Taiwanese tub"
  15. mapism

    mapism Senior Member

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    I fully agree with all previous comments about the somewhat weird behaviour.
    But I'm not so sure that it's just the helmsman to be blamed, because there are moments where the boat seems way too slow to respond to almost hard over steering, and that's the reason why he resorts to the b/t.
    My guess is that he's going with a rather strong current, and if there's a mistake it's that he feared going too fast in terms of SOG, so he kept a too slow STW (say 2 or 3 kts), hence drastically reducing the rudder responsiveness. So, maybe with a more "normal" STW the thruster would have been unnecessary, but as I said I'm just guessing.

    Ref. the stabilizers, I would think that they were not running at all in that video, for some reason.
    Though a very slow STW would explain also a much lower fin stabs effectiveness.
    Anyway, here's another video of the same guy, running in open sea and worse conditions, that shows how the same boat behaves with stabs running normally.
    She's still pitching a lot, definitely more than in the OP video, but as we all know there's nothing stabilizers can do for pitching.
    OTOH, rolling is pretty close to none, as it should be.
    Last edited: Feb 2, 2023
  16. mapism

    mapism Senior Member

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    Next thing you'll tell us that you'd rather cross an ocean with a Sunseeker than with a Nordhavn...? o_O
  17. Capt J

    Capt J Senior Member

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    No, don't put words in my mouth. Have you run several different sized Nordhavns???

    I have run dozens of these types of displacement hulled Asian brands of boats. A good number of them have some really scary handling characteristics. I ran a 60' Defeaver that had a hull speed of 8.2 knots. IF you got into a counter current doing 8.2 knots, the boat would do a 180 degree turn within 100' and almost throw you out of the helm chair, if you didn't back the throttles down to idle instantly as soon as it wiggled the first time. SO every inlet with an outgoing current, you'd have to slow down to 3-4 knots SOG. Several others where they'd hunt and veer 40 degrees left and right from your heading going in and out of inlets, just like this one is doing.

    Nordhavn has a great name and well in the end are a good boat. NOBODY tells you that the US branch has to spend 4 months fixing all of the factories screw ups before delivery to the customer and that for the first year, owners are having the dealer constantly sorting out all sorts of build/engineering issues under warranty.
  18. Pascal

    Pascal Senior Member

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    Looking at the video once again, it seems to me that the boat was going too fast approaching the cut and surfing the waves. If you look at the video in you tube instead of embedded here, you can zoom in. Overhead on each side of the garmins seems to be digital displays showing depths and GPS speed. Before entering the cut itself, there seem to be 11 to 12 kts surfs. Looking at the waves, the boat is definitely catching them…. While this should provide plenty of flow on the rudder and fins, it also means the boat will be a handful

    the ground speed also shows that he was going with the current and wind so conditions should have been manageable. Again, Dotham is a very safe cut and in this case he was not dealing with wind against current. Even in the cut at peak current, the speed wasn’t much higher unlike other cuts.

    the sound was a bit choppy that day but pretty typical. Had the conditions been rough, I can’t imagine why he would have gone the extra 20nm to Dotham when Galiot to the south and Conch cut to the north are just as easy. Whenever we run up and down the exumas we always try to minimize our time in the sound since the bank is deep and calm.

    finally, I can’t help wondering why he kept the thruster going for long period of times, especially later in the clip, without switching directions while changing direction on the steering wheel. If you need help to from the thruster to steer, wouldn’t you release the joystick when you start steering on the opposite direction?

    that boat sure seems to be a handful though.
  19. motoryachtlover

    motoryachtlover Senior Member

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    Mapism good observations as always.

    As Dockmaster pointed out it is easy to 2nd guess the guy from the comfort of my couch. But, I do think Mapism’s video begins to establish a pattern of mistakes that indicate lack of experience. He apparently didn’t secure his dinghy and scooter before getting underway. I can’t see where ratchet straps or steel cable is securing the dinghy (its moving around so slack somewhere) so now we got to put ropes on it on a pitching deck. One of ropes that is trying to secure the dinghy is slack and doing nothing. Then you hear the VHF speaking of a gale warning. I get it it is a Nordhavn and the Chesapeake bay but even still you have to anchor or tie up at the end of the day. Everything is worse when the weather is fighting you. I have made all of these mistakes and have learned and he will as well. It is part of boating and living for that matter.
  20. Slimshady

    Slimshady Senior Member

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    Only time bow thruster has been used was in new river. Couple of manatees traveling with us against the current. They weren't making much headway, were blocking the channel, making steerage difficult for us in a 73 ft trawler. Couple quick burps from the thruster and they moved to the side rapido!!