What is the Bayliner 2556 waterline length?

Discussion in 'Boat Design' started by David Swingler, May 1, 2024.

  1. David Swingler
    Joined: Oct 2023
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    David Swingler Junior Member

    I have been trying to figure out what the true hull speed is for a 25, my guess is that it's somewhere around 6.3 kts, but does anyone know what the actual waterline length is?
     
  2. mudsailor
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    mudsailor Junior Member

    Begs the question why…..
    And 6.3 is probably a bit high……but again why?
     
  3. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    25 is loa I’d say

    Take the bow and lay a plumb line off and measure back to the waterline. wild guess is 23’ based on pictures

    @mudsailor brings a good point

    for a planing hull, running at 6kts is gonna be pretty inefficient, in case you think otherwise

    I don’t claim the best expertise on the subject. My understanding is hull speed is important for displacement vessels, not planing hulls. For a planing hull; the efficiency happens out of the hole or barely movin.
     
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  4. David Swingler
    Joined: Oct 2023
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    David Swingler Junior Member

    thanks for the input! i mostly agree for a plaining boat, however im the crazy guy who is considering converting it to outboard Yes a 25-50hp Yamaha large prop and run about 6 kts getting hopefully at least 4mpg
     
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  5. C. Dog
    Joined: May 2022
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    Location: Coffs Harbour NSW Australia

    C. Dog Senior Member

    David it is an inefficient hull for your requirements, but you obviously have your reasons.

    Not the hugest fan of outboards on transom brackets, however wondering if it's feasible to mount the outboard behind the sterndrive leg so that either engine could be used?

    You could tee off the existing fuel filter out to the outboard, but use ball valves to isolate the non running one. Steering would be hydraulic with three way ball valves (or solenoid valves) and it would need separate throttle & shift control, maybe electric.
     
  6. David Swingler
    Joined: Oct 2023
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    David Swingler Junior Member

    Thanks, ya its a cool idea; I'll think it over
     
  7. willy13
    Joined: Jan 2022
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    willy13 Junior Member

    A 9.9hp high thrust is common on go fast fishing boats your size (trolling and get home safe). From reading posts over the years it seems 10 hp will push them to hull speed at or near WOT. So assuming the 1 gal of fuel per hour per 10 hp at WOT is correct, you should see 6mpg with an ineffecient hull as these fishing boats are similar in hull type as yours. This is just my guesstimate.
     
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  8. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    I’d go a bit higher than 10hp. You want a bigger prop for better weather helm.
     
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  9. Chuck Losness
    Joined: Apr 2008
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    Location: Central CA

    Chuck Losness Senior Member

    The fishermen in my area all seem to have 9.9 high thrust outboards for trolling and as a get home motor. If it is your only engine I would go a little higher in hp. Maybe 15 to 20 hp. Bayliner does have some older models that were semi-displacement hull shapes. Look for 2670, 2270 and 2260. Some of those owners have converted to high thrust outboards in the 25 hp to 50 hp range.
     
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  10. willy13
    Joined: Jan 2022
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    Location: Canandaigua NY

    willy13 Junior Member

    yeah get bigger than 10 hp, only used 10 hp to estimate mpg and show that your 4 mpg is probably attainable. A high thrust 25hp might be perfect .
     
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  11. Ike
    Joined: Apr 2006
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    Ike Senior Member

    That's what I have on my 18 foot Sea Ray. A high thrust 9.9. My speedometer doesn't even register anything under 10 mph, and the 9.9 does not push it past the 10 mph. So I assume it's running around 9-10 mph. It's great for trolling. It can throttle down to about 2 mph which is a good trolling speed. On a 25ft boat it would probably go 7-8 mph. Just guessing.
     
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  12. David Swingler
    Joined: Oct 2023
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    David Swingler Junior Member

    that's exactly what i am thinking/hoping.
     

  13. David Swingler
    Joined: Oct 2023
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    Location: Seattle Washington US

    David Swingler Junior Member

    another question i had was weather the really cool mercruiser shifter and throttle could be adapted to the outboard?
     

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