View Full Version : Small Flats/shallows boat hull design question
07-05-2006, 08:48 AM
I have been reading/hearing some conflicting stuff on hull design.
For a shallow runner, with flat top deck… is it better to have a slightly curved hull or a flat hull with runners? I have heard both… I’ve heard it is always better to have a curved hull with a slight V bow. And I have heard that it is wasted on a small boat… I want around a 16x4’ boat… I have been looking at designs, but the ones I really like are to expensive and complicated. I would like to keep it as simple as I can and as inexpensive as I can.
A simple flat bottom Jon with a deck… but some guys around here have been telling me I wont be satisfied… that I should build the V right off.
So, I come to the experts… what do you guys think?
07-05-2006, 08:52 AM
depends entirely on what you want to use it for...and where you intend to use it....
Most boats are purpose built for specific conditions/areas/purpose...
Do you wanna fish in a pond...run across a large lake.....open sea....good weather? trailerable?...do you want to be able to survive a squall?.....sleep aboard?....
Lotsa questions.....before you get the answers....
07-05-2006, 09:16 AM
Wow… ok, I want it mostly for a calm river, but I would like to take it on the small inland lakes… they can get 2, some times 3 foot swells. I want to be able to stand on the deck. And be big enough for two guys comfortably. I have a trailer, I will customize to the boat… I have a 10hp and a Evenrude 50 (that might be to big, if it is I will trade it on something smaller) I would really like a standup consul, but I think I am reaching there… although I have the steering wheel all the cables and pulleys and the throttle assembly with the Evenrude….
How wide should I go? Is a 4 foot bottom wide enough? Could I use the Evenrude if I make those foam filled flotations off each side of the transom?
I realize I don’t know the correct terminology, and I sound rather simple minded, but I am a good carpenter and can design on paper what I envision… I have never built a boat, so I thought I’d ask before I started…
07-05-2006, 10:12 AM
Anything that rides in the top few inches of water is pretty much going to feel what is in that water. The vee might alleviate the head on into light chop a bit but I don't see it ironing out the rough much. I always notice that when in any boat, whether a full blown vee hull flats boat or a flat bottom,it's just unpleasant to be out there when there is 2 ft chop.Seems the only real way to navigate, making any time at all without losing one's kidneys, is just below planing speed with the bow up. I avoid days like that because never mind getting out there in it but sitting in it trying to fish just isn't worth it.
The one thing I hate about jon boats is that slapping sound of even the lightest waves smacking against the front of the hull, even just sitting at anchor. Bang bang bang bang bang. Typically,we ditch the boat in the mangroves and wade fish. 4ft is a bit narrow for a deck boat. By the time you add the weight of a deck on top to support you it is well on it's way to being top heavy before you even stand there. It can be done but it requires some balance by the fisherman.5ft would be "minimal" for a 16ft'r.
07-05-2006, 10:41 AM
SFC Hall... mate have a gander around (look and search for sorry its an Aussie lingo thing) for threads about what you blokes call "flats boats" I know there was one very recently and I know a forumite who calls himself Davesflatsboat has designed and built one
twin hulls v entry on both stand up console good for a couple of stocky fellas and a good sized esky (err cooler that Aussie thing again) good for small water and a bit of chop and would take the 50 happily
Seems to me that would suit near on perfectly other than the 4ft wide thing that is... Im not overly sure here but 16 or 18ft seemed about right for the two boats in question if memory serves (which sometimes it doesnt but this time I think it is if you know what I mean)
Anyway I think thats what your after??? possibly??? maybe?? could be?? sigh sometimes I wonder at myself :rolleyes: then I get over it :D
First off, flat bottom jon boats are pretty much for shallow water and don't offer a lot of versatility. Everyone is searching for the all in one hull design that runs very shallow while offering great stability and comfort in rough conditions... lots of compromise has to come into play.
If you take a quick look at the following thread you will get an idea of where you can go with a little professional help and some research....to define a craft that will meet your needs for a long time.
Pipefitter is right, go for a bottom width of at least 60" and you will be much happier with the overall stability. If you build a boat that has a nice "V" hull and runs good in rough chop, it will not be as shallow draft as a jon boat... most fisherman are trying to get the most features packed into one boat and you have to make compromises. Note: An aluminum boat that would work would be the Generation 3 16'X56" semi'V for discussion's sake and general parameters.
Remember, with an outboard hanging off the stern, you will pretty much be stuck with a draft of 14-15" give or take, so a moderate "V" hull will not hurt your overall draft equation. You can easily build a 16 footer that can handle the 50 hp engine (Glen-L's 350 lb console skiff comes to mind but is overbuilt) but building a lighter craft powered by the smaller engine has advantages to be considered. Personally I prefer a boat with a little more heft so that it has a solid feel in the water especially in rough conditions so I don't lean towards really light hulls. I've had my time with light weight aluminum boats a long time ago. A 300 to 400 lb hull with the 50 hp outboard would be a nice rig for your description and could be layed out exactly the way you wanted.
And,no you don't need the boxes on the back end of the transom (sponsons) as they are used in really shallow waters to keep the boat level and handle the weight of the outboard at the stern. Sponsons have their own set of advantages and disadvantages and you don't want or need them to deal with.
There are many existing boats that would work for you you just have to narrow down your criteria to narrow down your choices. Perhaps you would be best served with a "V" or semi "V"hull that has a shallow entry and ends up in about a 6-10 degree deadrise hull throughout the rear 2/3 of the hull. You would want the bow to offer a decent degree of trackng. As far as width and other parameters I would suggest you contact a professional like the designer of my skiff because he can offer an educated solution to the set of parameters you feel are important...and develop a simple set of stitch and glue plans for your needs...at a very reasonable cost or modify some existing plans... email@example.com Tracy's laminated sheer decks offer a great way to build a hull that is very stiff and strong but not overbuilt. You have lots of versatility in laying out the interior, amount of freeboard, storage, helm station ...etc. Tracy would also be a great source of information when you started the build.
I always am a bit perplexed when folks are trying to find pre-existing plans for a boat to meet their needs but will not consider having a boat drawn up specifically for what they want or even having some existing plans modified to meet their needs...which does not cost all that much...not to mention having a professional opinion as to solutions to their boat need problem. I assume we're talking stitch and glue or some other variation of epoxy composite construction. I think I paid around three hundred dollars for complete development of my plans in TWO sizes, the 16 foot and 18 foot version of the Texas Flats skiff. These kinds of boat are pretty simple. I designed my own console and storage layout. Considering all the money and time invested in building ones own boat it seems focusing some time and money on the right plans seems a good idea.
07-05-2006, 10:14 PM
If I was to build a flats boat,I would like RodB's boat. It would be perfect for our waters here.I also am an advocate for a slightly heavier boat. If nothing else,they just feel more substantial and a bit more quiet. I just built the boat heavier and handed out jenny craig coupons to my portly fishing buddies. :)
07-06-2006, 07:05 AM
Here's what I found it comes 16' or 18'. The 18' isn't advertised but offered after I asked about it. Your needs sound about what mine are so this might fit the bill.
Good Luck. Hopefully we'll be posting pics about the same time.
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