Request your input on my design

Discussion in 'Boat Design' started by richardf, Jul 15, 2013.

  1. DCockey
    Joined: Oct 2009
    Posts: 5,091
    Likes: 556, Points: 113, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

  2. hambamble
    Joined: Jul 2012
    Posts: 52
    Likes: 3, Points: 0, Legacy Rep: 28
    Location: Gold Coast, Australia

    hambamble Junior Member

    If you want to get the chine in the water, flatten the V in the bottom of the hull. You will notice the other designs suggested are all flat bottomed (or close to it) where as yours has quite a lot of deadrise
  3. DCockey
    Joined: Oct 2009
    Posts: 5,091
    Likes: 556, Points: 113, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

  4. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,401
    Likes: 1,034, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    Looks like a good idea if the ICW is protected enough, which could be doubtful.
  5. tunnels

    tunnels Previous Member

    What part of Aotearoa you from ah fella bro ???
  6. 805gregg
    Joined: Apr 2010
    Posts: 57
    Likes: 1, Points: 0, Legacy Rep: 20
    Location: Ojai, Ca

    805gregg Junior Member

    You built a flat bottom row boat, now your a boat designer?
  7. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,401
    Likes: 1,034, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    Well, you have to admit the design is "different" 805gregg ! I do hope the OP is not nursing intentions to actually build it, as I see only disappointment in it.
  8. tunnels

    tunnels Previous Member

    second boat you are classed as designer
    third boat an expert and
    fourth a professional with practical experience
    Fifth boat then you get the golden anchor award and go into the book and recorded for ever and ever !! :confused:
  9. HakimKlunker
    Joined: Aug 2009
    Posts: 274
    Likes: 10, Points: 18, Legacy Rep: 146
    Location: Thailand

    HakimKlunker Andreas der Juengere

    Richard, you mentioned earlier that you want to begin building in December.
    When I see your sketches, I think that you will have to rush and catch up on the design side. You will also need some time to source (and negociate) building material, get set up in your new place, etc.
    If your intention is only to get your boat quickly and in a very affordable way, you might be better off to look for an existing design.
  10. rwatson
    Joined: Aug 2007
    Posts: 5,884
    Likes: 312, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    The attraction of ignoring proven plans and of building ones own amateurish design is a very real psychosis.

    Its the " Ikea Affect "( google "The “IKEA Effect”: When Labor Leads to Love ") , a study about stuff that a person builds, becomes extremely valuable in their eyes.
  11. Milehog
    Joined: Aug 2006
    Posts: 469
    Likes: 59, Points: 28, Legacy Rep: 215
    Location: NW

    Milehog Clever Quip

    Design and build a dinghy. Show it off with pride.
    Build your cruiser to plans. You will save years of time and not waste thousands upon thousands of dollars.
    Projects as large as building a boat are stressful on relationships especially when it is realized the amateur or free design is a disaster.
  12. messabout
    Joined: Jan 2006
    Posts: 3,227
    Likes: 374, Points: 83, Legacy Rep: 1279
    Location: Lakeland Fl USA

    messabout Senior Member

    Richard; please do not feel that we are questioning your general level of intelligence. You asked for advice and you will get good advice from most of the respondents here. You may not like what they tell you. Your posts have revealed that you are not ready to design your own boat. Yes, you can design and build a boat but it is not likely to give you a desirable result until you know a lot more about what works and what does not.

    Start with the drawing that you furnished on post #11. This is to be a displacement boat but you have given it no rocker. A disaster for a displacement type. Post #14 you have done your design work backward. The normal way to do it is to do a careful estimate of the total load the boat is to carry. You have done that but you are trying to make a preconcieved shape fit the displacement estimate. Do it the other way around. Design the immersed volume to meet the need. Have you calculated the prismatic coefficient for the shape that you have drawn? Have you calculated wet surface area for various bottom configurations? Displacement boats favor lowest practical wet area. Different cross sectional shapes yield different figures for a given displacement.

    Where you place the forefoot in running mode is an item of interest. That part of the boat is influential in whether the boat maneuvers well. Poorly placed it can make the boat "Hard mouthed" and it can set up uncomfortable, even dangerous, twitchy behavior in quartering waves or wakes.

    You have arbitrarily decided that 3 to 1 length beam ratio is good. The boat will work better underway if the ratio is much higher. It will go faster for a given power and use less fuel too. It might even ride a little better. You want the stern to be wide, for deck space I presume. OK make it wide on deck but not at the waterline. There are many more details, other than these, that need to be addressed.

    I hope that you will take this critique as kindly as it was intended.
  13. tom28571
    Joined: Dec 2001
    Posts: 2,474
    Likes: 117, Points: 63, Legacy Rep: 1728
    Location: Oriental, NC

    tom28571 Senior Member

    There are many stretches on the ICW that very often do not qualify as "protected water".
  14. richardf
    Joined: May 2013
    Posts: 44
    Likes: 0, Points: 0, Legacy Rep: 6
    Location: Michigan

    richardf Junior Member

    Please review the latest iteration in my boat design. I am still about 1000 pounds shy of getting the chines immersed. I don't want to reduce the aft deadrise any further, and I want to keep the sharp entry, large deadrise forward. In this situation where lightweight outboards are going to be used, instead of a heavy midships diesel, and the use of lightweight skantlings, how do you get around this dilemma of not enough empty boat weight to sit on the lines. How would you change the bottom profile and sections to move in the right direction?


  15. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,401
    Likes: 1,034, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    Your latest rendering is beginning to look like a boat, but we can't see any waterlines. And if plywood is the intended hull material, the forward portion of the bottom won't be happening, it needs to be a developable shape that takes account of the limitations of bending the material, both in terms of radii and not having compound curvature. You need to be familiar with those requirements, and how to go about drawing it up.
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.