Looking For More Information On River Jons

[frozennortherner]

I am planning on building a jon boat or possibly some other form of flat bottom boat and need more information on the speed, power requirements, and handling of long, moderately narrow beam, moderately rockered, flat bottom hard chine hulls in the lower semiplaning speed range.

Does anyone have real numbers for how much aft rocker a Shawnee 2048 has. I have heard they will stay level at well above hull speed if there is a lot of weight in the bow. Many folks on the woodenboat forum insist even a small amount of aft rocker automatically results in a displacement hull, something I know there are exceptions to.

with a heavy load (ie, 3 or 4 men, and some fishing gear and their catch) how fast will a shawnee 2048 go with say, a 9.9 or a 15. Will it always plow at moderate speeds or will outboard fins and keeping the bow weighted down cure this. I read about a mildly rockered skiff designed by Atkin, a slender 14+ footer that would plane 2 or 3 people with 4 hp. Operated normally it would nose up and porpoise if any attempt was made to go faster than hull speed, but trimmed level it would be hard to tell if you were planing or not without looking at the wake. It planed more like a sailboat, getting most of its lift from the middle instead of the stern, and would smoothly ease thru hull speed and "seem to levitate". The big question is if a rockered river jon can be made to do the same thing, and if a larger pointed bow skiff with a similar rocker profile to the large jon boats can be made to do the same.

I see a lot of full planing hulls where I live, most of them very inefficient, and believe if more people knew more about true semidisplacement types it would make a lot of people happy. I am aware that most people who sightsee on local rivers like to go 7 to 12 knots, precisely the point at which most planing runabouts are at their least efficient, and even more importantly, throwing their biggest wakes and handling at their least safe. Up in the northeast, and probably most other areas as well a hull optimized from the beginning to handle well in this speed range is sorely needed and would be deeply appreciated. Unfortunately most people I have met are unaware of the shawnees, supremes, and playcrafts even existing, even those for whom just such a boat would be their best option.

I intend to build a river jon or plywood motor sharpie someday (not this year; not enough money)because I want something larger than my 14 foot wagemaker utility boat for freshwater fishing, volunteer work, and sightseeing that will be simple and affordable to build and get good fuel economy. My favorite (read the one I best trust not to strand me) motor is an air cooled 5 horse outboard and my largest (read larger of my only 2 functioning motors) is an evinrude fastwin 18. Both were cheap craigslist deals, but work just as well as something triple their price at a marina. I intend to use the 5 horse for water quality sampling and freshwater fishing due its above water exhaust and low fuel use, and the big evinrude for sheltered harbors/salt marshes/etc or anywhere speed is of concern.

[gotmuddy]

white river boats dont plane out like a normal boat. a 15 also will come nowhere near planing with 4 people in a 48" wide boat.

[grizwilson]

Check out:

http://www.longboatoutfitters.com/

I run two white river boats, both 21 feet, one an aluminum 36" floor, rockered on both ends mostly floating and where I do not want to bang up my glass boat. The other a 42" floor Champion, that is flat and smooth with a slight rocker at the back. Love both. The only way I would look at a total flat boat is to run a jet. Trouble with a jet in this area and White River is rather than the small gravel like on the Current we have many boulders that hide just under surface, when you hit one at speed that is needed to plane on a jet, hard on the boat and often dislodges passengers (alway wear a kill swithch) The other issue with the jet (I can talk bad because I have one) They suck up that coon tail and become clogged with leaves in high water, they are noisy and too large to run legally on the Buffalo or Crooked. A river jon wilh a 9.9 will float over most stuff and go most places. That said the Supremes are beautiful boats, (again I can talk bad because I have a nice finished boat) a source of pride and a joy to fish out of. That said it is a river boat and is going to get banged, a Shawnee or J&S in a plain type finish is a lot easier to stomach than that beautiful chips of red fiberglass and gel coat floating down the beautiful clear water..... my 2 cents

g

[frozennortherner]

Piscator on the Playcraft river skiff (albeit only the 42"er): quote]The 15 HP 4 stroke Honda prop on the demo drove the hull onto plane easily in a couple of boat lengths or less. Top speed was surprisingly good The load was 3 people and a battery.

are the shawnee 48"ers really that much slower? there is an extreme distinction between nowhere near planing and planing in less than twice a boat's own length and it doesn't make sense to me that an extra 4 inches of bottom width would be responsible for that difference.

To reiterate my original questions:

At what speed will a 10 or 15 prop motor push a heavily loaded river jon?

how big are the speed differences between say a 42 and a 48 bottom?

what about one with just 2 people aboard?

How much rocker does a shawnee have.

I use the term planing differently than normal powerboaters do, i simply mean any normal, sustained instance of traveling faster than hull speed other than plowing. a boat with a hull speed of say 5 knots traveling at 9 to 12 knots semiplaning on its midsection instead of the stern, but reasonably level and not throwing up a huge wake Would count under my standards, and in fact is the very behaviour I am seeking.

An interesting story I once read (I forget where exactly) involved a smart little stunt in Louisiana involving a restored cypress Bateux and a girl on waterskis. Apparently the 24 footer dragged the (110 lb iirc) girl onto ski at 12 knots and without towing her could make 15. the engine in question was an 8 horse Nadler inboard from the 1920s. I find this surprising but believable because I have seen video of a very similar boat with the exact same make of engine planing long before full throttle.

[junkman]

I guess it's all in the boat but my 12' Duranautic v bottom with fishing gear and two small adults and a kid will in no way ever reach plane with my 9.8. If a flat bottom will make that much difference I guess I need to get one.

[taxidermist]

A 48 inch Shawnee is going to be slow with that large a load and 3 or 4 people and a 15hp. it will be ok with a 10 pitch. I ran a older Shawnee with a 25hp two stroke yamaha and SS prop and with four people and gear it would zip up river, even with 8 unit online. With the 15 four stroke Merc and the 9 pitch is was a bit slower and under powered for 8 units and four people.

I just picked up my new Shawnee a couple weeks ago, 20Hp Merc four stroke, Its going to be about right in power and speed. Easy very easy on fuel.See the other post.

[gotmuddy]

Piscator on the Playcraft river skiff (albeit only the 42"er): quote]The 15 HP 4 stroke Honda prop on the demo drove the hull onto plane easily in a couple of boat lengths or less. Top speed was surprisingly good

The load was 3 people and a battery.

are the shawnee 48"ers really that much slower? there is an extreme distinction between nowhere near planing and planing in less than twice a boat's own length and it doesn't make sense to me that an extra 4 inches of bottom width would be responsible for that difference.

To reiterate my original questions:

At what speed will a 10 or 15 prop motor push a heavily loaded river jon?

how big are the speed differences between say a 42 and a 48 bottom?

what about one with just 2 people aboard?

How much rocker does a shawnee have.

I use the term planing differently than normal powerboaters do, i simply mean any normal, sustained instance of traveling faster than hull speed other than plowing. a boat with a hull speed of say 5 knots traveling at 9 to 12 knots semiplaning on its midsection instead of the stern, but reasonably level and not throwing up a huge wake Would count under my standards, and in fact is the very behaviour I am seeking.

An interesting story I once read (I forget where exactly) involved a smart little stunt in Louisiana involving a restored cypress Bateux and a girl on waterskis. Apparently the 24 footer dragged the (110 lb iirc) girl onto ski at 12 knots and without towing her could make 15. the engine in question was an 8 horse Nadler inboard from the 1920s. I find this surprising but believable because I have seen video of a very similar boat with the exact same make of engine planing long before full throttle.

your math is flawed. The boat is 6" wider. a 48" wide boat has a surface area 84 sq/ft, a 42" wide boat has a surface area of 73.5 sq/ft.

I have a true flatbottom monark that is 18x36" and my 9.9 will gps at 17mph with a 9 pitch and 14 with two people. the same motor on my old boat wouldnt even plane out. It was a 15' x 42" fiberglass boat.

I have piloted a 21x32 shawnee and a 21x48 JS boat, both with 9.9s and the speed difference is tremendous.

The river boats used on the white are not planing hulls.

[Troutman]

I've been taking in all this good info on these river boats. I live in the Delta, but frequently fish in the Ozarks, we have a place in sharp County, and have family near Heber Springs, so I fish Little Red, and the White quite a bit, especially in the Winter. Anyways, I am really close to ordering a new boat from Supreme, I"ve been researching and like what I see in the supreme. I also plan to use this boat in the good ole muddy St. Francis river here in Clay county to chase flathead during low summer water. Here, very few fish the River where i like to fish it because of the shallow sand bars, I believe with one of these boats, i could also run the river where others can't. My question is for those of you that run both kinds of boats, will a L48 Supreme run more shallow than my 1856 War Eagle. My boat is Semi V'd so it will eat up a crooked river, i love it, but on these Ozark Rivers, it doesn't seem to float very shallow enough to keep me from being nervouse around all the rocks. I fished in a Topwater boat last winter in the Little Red, was very impressed with the water we went over, will the Supreme float in as shallow water as the Topwater? Thanks in advance for any Info!!

[rps]

I have had shallow draft jons and a Supreme 2000. The Supreme ran more shallow. Without arguing over the math, think this way -> the surface area of the Supreme is high because of its length. The flat metal jons are wider but shorter. The difference on the rivers is that the "deep" water is frequently only a few feet wide and the skinny boat can navigate it more easily. If you watch a good White River guide on shallow water days you will even see them lean to pull the offset prop slightly higher out of the water to slip down a river cut barely wider than their boat. Btw, when I fished the Supreme I often stood on the front deck. It was very stable.

[gotmuddy]

The supreme will float in a few inches less water than your current boat, and you can take off in a foot of water and go full speed.