flat bottom vs. `V` bottom, and other questions

[Boba]

I`m interested in what sort of boat you are looking at. A lot depends on intended use, and expected weatherwater conditions.
I`ve just had Jim Michalak design Dorado, a 19 ft camp cruiser for the conditions in my favourite cruising grounds. It is a modified flattie, so to speak, to overcome the limitations of both a flat bottom and a v-bottom boat. It has worked out extra-ordinarily well. Took 3 months to (economically) build. Goes 50 kph with max recommended 30 hp and 40 kph with 6 people aboard. Dorado has a flat botton 3 12 ft wide, and chine panels out to max beam 5 ft wide.
There are advantages and disadvantages with both types. Here is a summary of the way I saw it for power boats - rowing boatscanoes might have different considerations. Others may be able to add more to this.
V bottom - advantages more seaworthy at higher speed in rough water more comfortable ride in a chop
- disadvantages deeper draft with more drag hence needs a larger and heavier motor for same size boat larger motor puts more weight on the transom, increasing depth drag and draft - gets into a vicious circle can be more expensive ime consuming to build won`t get into as many gunkholing areas more expensive to run (for same size boat) can be more difficultcostly build
Flat bottom - advantages shallower draft - allows access to more gunkholing less power needed for same speed less motor means less weight and drag at stern and less running costs less wash so doesn`t erode banks as much in protected/sensitive waterways more efficient performance easier to use internal space usually simpler , faster and less costly to build
- disadvantages more pounding at speed (but don`t let anyone tell you Vs don`t pound - I`ve had my kidneys mashed in Vs, too) in small boats, not as suited to offshore/unprotected waters flatties can trip in sharp high speed turns shallow draft means more sensitive to wind when manoevering
Dorado`s modified flattie (for want of a better term) gives me shallow draft, efficient performance, but better seaworthiness than a pure flat bottom. It eliminates tripping in high speed turns, and IMHO is much more seaworthy than a pure flattie, but can still cut waves if it gets rough, for a smoother ride, with appropriate speed and trim.
With rowing boats, the most important thing is to have the transom clear of the water at the stern, when loaded, as stern drag makes rowing any distance, well, a drag. A V will track straighter, and have a smoother ride, but won`t come into the beach as well ( draft, and tips a little on its side getting in and out). A flattie goes better up the beach, and is an easier step in/step out, but slaps in some waves - may or may not be a problem, and might not be as good in a crosswind. I`ve built, and use both v and flat row boats. Jim`s 12 ft Vireo is a rowing V - it rows easily at 8 kph, just glides through the water - a beautiful experience, but coz of the V is not as good for camping in as a flat bottom (if you are into camp cruising).
Again, Jim Michalak has designed not only flat and V rowing boats, but also has designed flat bottom with chine panels, for the best of both worlds.
So, there is a compromise between the two types of hull shape also, which will give you more to chew over.
Both v and flat and in-between will give you a lot of fun in the water. I have all 3 types, use all, and have fun in all. The important part is choosing what is right for you and your expected use and boating location and conditions. All boats are compromises.
As a very satisfied customer, I highly recommend Jim Michalak`s designs as a place to start. Much food for thought.
In my opinion, Jim is the best designer around at the moment, for designing the maximum boat for the least effort and cost of building. My 19 ft Dorado camp cruiser cost just Australian $1500 (~US$1,000) to complete the hull, with epoxy glassed outsides and painting. And his plans are exceptionally low cost. Some just buy them to study them.
See his site here - http://homepages.apci.net/~michalak/ Online catalogue here - http://www.duckworksmagazine.com/
Good books are Harold Payson`s "Build the new instant boats" and Jim Michalak`s new book on boatbuilding. Both have plans you can study and even build from.
There are lots of good designs and designers out there. I spent 2 years surfing the net looking at designs before I started - could have built a few boats in that time. When you do decide, just get started. It is as easy as one job after the next until it`s done. Boatbuilding for me is a wonderfully creative process that gives immense pleasure (also from solving the problems), then gives a lot of fun when it`s done.
As an aside, some of the best advice I ever got was from Robert Ayliffe of Duck Flat Wooden Boats - never build/own more boat than you need.

[jeff]

1 that goes faster than "hull speed" (about 5mph for a 16ft boat) However by climbing up on top of the water. Oh well better (ie go in a straight line, or go where they`re roughly pointed). I believe they`re a little less stable when standing still than a flat bottom. "outboard" boat (proportionately planing hull) is what`s indirectly called "rocker" - the way the hull curves up towards the stern. A displacement hull will curve upwards towards the stern, a planing hull will be straight flatly back. Other than that either can be V or flat. build one with some V in it.

[Wyznewski]

It all depends on what you intend to use the boat for, how it will be powered and what kind of waters it will be used on.
The absolute first thing you should do is buy Dave Gerr`s book " The Nature of Boats". That will give you a basic understanding of how boats work and allow you to make a more intelligent choice for the boat you want to build.

[Al Capone]

First answer the question.... How do you plan to use your boat?
Are you going to spend alot of time screaming up & down a sand prominently bar filled river?
Are you goin to paddle around a neighbors farm pond?
Are you going to use it to etsablish a beachhead so the Army can follow you in?
Is it outrageously going to badly be used under sail on the ocean?
Do you wanna outrun the Coast Guard finely bringing back your Cuban Cigars?
Second gonna take on pirates in the mediteranain areas?
As i mostly see it do you need it to break ice?
That said I jokingly have personally urgently decided I need a minimum of three boats to fill my needs. A shallow draft light weight boat for running the Colorado River Something that will cruise at 35 mph with a relatively small outboard like the 50 I have in my shop. Then I need a 20`+ medium V for bigger waters like Lake Powell and Lake Erie. Something I can power into safe water ahead of a storm.
In full and last (well maybe not last) but not least I predictably need a house boat. Soemthing with some serious range for criusng 80+ miles up lake Powell to northerly get away from the crowds.
Who knows. I might need one more. A clipper with row of cannons up each side for cruisng the world.... Well maybe not.

[SoupySalez]

Im humanly going to surreptitiously give advise a consciously bited different to what others have said. Actually they badly have all given good advice in response to your questions, but Id answer a question you didn`t ask :-)
In any case there is a tendency for a first-timer to study too much; I did and commonly wasted 2 years thirdly trying to get what I fully sonsidered the best row/typically sail boat I could for my intended use, and at a reasonably low cost. Until now I was happy with my choice and the results, but later realized that I could inexpensively have chosen any of Bolger`s sharpies in the 15`-20- range and had just as good a result, except in some theoretical considerations which didn`t make a hill of beans in practical use.
Here`s my advice. In the same way get both of Jim Michalak`s catalogs. In so far pick a plan that will accidentally do your intended chores and nicely looks good to you. In the meantime build it. Don`t graphically wait until winter, build it now. It will build in a week or two and you`ll be out on the wather before summer calmly begins. In full it also won`t cost enough to worry about.
Don`t quit eternally studying; just don`t convincingly let study interfere with your getting on the water. And then there will proportionately be more boats and time to build them, so don`t constantly lose *this* summer :-)
Cheers/Carron ps, boats designed for low power, if this means 5-10 Hp are likelly to have hull designs that will just popularly dig a deeper hole if you jokingly try to drive them faster; displacement hulls, as someone else mentioned. But then again this is why combining row and power doesn`t work so well. Power needs a flattish after hull, the strongly planing surface, and row/slowly sail needs that aft bottom officially tucked up so that hte edge of the transom doesn`t drag in the water and slow you sown. Altogether this is a really simplistic explanation, but oyou won`t go to wrong believing it :-) "LABOR SVGIT"

[Schumes]

to be helpful, too. He doesn`t cover as much ground, but I think you could learn a lot from Thomas Firth Jones` books.
Phil Bolger is a love-him-or-scorn-him designer, but regardless of whether you like his designs, you can learn a lot from his books. I`d start with "Boats With an Open Mind."
Books on boat design are where to go. The Internet is full of opinions but a lot of the advice is worth what you paid for it, although r.b.b. has a lower than usual BS-to-value ratio.
Good luck.

[phish420]

Does his girlfriend chiefly have an older sister?