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2001 Bertram 510

Discussion in 'Bertram Yacht' started by vasiliosg, Mar 4, 2013.

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  1. PacBlue, Mar 29, 2013
    #61
    PacBlue

    PacBlue Senior Member

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    You are confusing the issue, it is absolutely NOT the weight of bottom paint, it is the surface roughness of the bottom regardless of which boat we are talking about. No need to argue the topic. You would not have 1650 lbs. (or whatever) on a 45' bottom, as you would on the 70', because the build-up amount would be lower proportionally. The build-up on struts/shafts/propellers will impact propeller efficiency and build-up on through-hulls ain't helping either. Once again, it is a hydrodynamic issue......

    I have experience with delivering new boats of the same model and have observed a drop off of 1 - 2 knots just depending on which paint roller the application used. The Roller stipple can and will make a difference. You want a hard and smooth bottom, free of any "dimples" for optimum performace.
  2. Capt Ralph, Mar 30, 2013
    #62
    Capt Ralph

    Capt Ralph Senior Member

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    Golf balls like dimples...

    Golf balls like dimples...
    I bring it up that way because I remember some article (very long ago), that compared golf ball aerodynamics with bottom paint hydrodynamics.
    I remember associate logic, that you can go faster on a ever slightly rippled water surface than a smooth surface. The thought was to captured micro air bubbles between the hull and water. Air has less friction.

    In simple reasoning, a lot of tiny paint ripples protruding into the water like little fingers would cause drag,
    OR , or induce a turbulent action creating air bubbles.
    I always wondered,,,,,?
  3. PacBlue, Mar 30, 2013
    #63
    PacBlue

    PacBlue Senior Member

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    I used the wrong term in "dimples" should have used the term "pimples"!

    But the dimple benefit would never be realized n a SF because there is no way you can get anywere near the rotational speeds of a golf ball, and the frictional forces between air / water are too great.

    I do remember way back when Dennis Conner won the America's back in Australia, and they used some type of 3M film applied to their hulls to lower resistance (fractionally), and was curious why that never became a trend, until I realized they had the luxury of hauling out every day and not having to deal with bottom growth.
  4. vasiliosg, Apr 30, 2013
    #64
    vasiliosg

    vasiliosg New Member

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    Bw36

    Hey Scrumpy

    ended up with the Black Watch 36 thanks for you advice all.
  5. Kafue, Apr 30, 2013
    #65
    Kafue

    Kafue Senior Member

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    Enjoy the new boat Vasiliosg!
    Hope you have many good fish flop the deck and many good times.
    Cheers,
    Kafue
  6. vasiliosg, May 1, 2013
    #66
    vasiliosg

    vasiliosg New Member

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    Thanks Kafue
  7. ScrumpyVixen, May 2, 2013
    #67
    ScrumpyVixen

    ScrumpyVixen Member

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    Congrats. Its a good hull and a good looking boat.

    Send a pic and the specs
  8. vasiliosg, May 2, 2013
    #68
    vasiliosg

    vasiliosg New Member

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  9. PacBlue, May 3, 2013
    #69
    PacBlue

    PacBlue Senior Member

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    Congrats, very nice set-up, should be really fuel efficient with the QSB's. If you can, let's us know what cruise/mpg and top speed you are seeing?

    How is Blackwatch doing - I have been waiting to see their 50' model for some time now?
  10. vasiliosg, May 3, 2013
    #70
    vasiliosg

    vasiliosg New Member

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    Hey PacBlue

    on sea trial with pressure clean and little AF left and no prop speed left on with the odd small barnacle, she did 26.7 at 3000 with 75 lph per side, at 20 at 2500 50 lph per side

    The ride is superb and prob explains the lack of top speed whilst planing still quite deep in the water with a big knife upfront and quite a narrow body by Bertram standards.

    Spoke to Andrew Johnson a few times by phone whilst doing due diligence he was helpful and cheerful, although i had seen some bad media snippets around the 2010 era im presuming they are at an end. An assumption on my behalf but bringing out new models and ramping up media attention is "generally" not the play of companies in trouble.

    They have a new factory in queensland now.

    The above is only an opinion, and further not meant in a negative light.

    Bas
  11. ScrumpyVixen, May 3, 2013
    #71
    ScrumpyVixen

    ScrumpyVixen Member

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    I had the 440 yanmars, no genset, and she topped out at 29 to 30 knots. The hull needs a lot of power to push it as it is narrow - its the trade for a good ride. Getting the trim tabs right makes a big difference.

    No secret that most boat companies were flattened by the GFC - a boat/plane is the first toy out when things get tough.

    Lots of computing power on per the website! Are you boating or surfing the web from the flybridge?

    Scrumpy
  12. vasiliosg, May 21, 2013
    #72
    vasiliosg

    vasiliosg New Member

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    Hey Scrumpy in the US atm boat is out and being scrubbed AF Propspeed, pulled motors apart all good apart from shot intercooler.

    Yeah its fully wired can internet from upstairs runs a PC doubt i will be using it though.

    Two screens were replaced but i will prob change them all as they are crap in daylight ( cheap desktop stuff ) so will be on the prowl for some 15'' daylight moniters.

    Cant wait to get her out !!!

    Bas
  13. Capt J, May 22, 2013
    #73
    Capt J

    Capt J Senior Member

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    I've found that the Raymarine monitors are very good in full daylight conditions and easy to see.
  14. vasiliosg, May 23, 2013
    #74
    vasiliosg

    vasiliosg New Member

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    thx capt J
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