Draft difference: Flat bottom vs. Mod Vee

[dsuden]

We live on a river with a lot of shallow spots, which become more "plentiful" as the summer wears on. We need a shallow-runner. I tried out a Triton 16' mod vee with decking and a 25 HP engine, welded, probably .01 gauge aluminum, and it had too much of a draft; the lower tip of the prop fin was probably at least two feet below the water.

Back to the drawing board!

As it stands now, my guess is that we should probably go with a flat bottom, lighter gauge aluminum, riveted, and as wide as possible for more buoyancy. I'm gun-shy now about a 16' length. Maybe 14' would be lighter, thus less draft. Would translate into less demand for horsepower too, which would result in a lighter motor, less tail drag. We have another boat we can use for lakes and "wavy situations," so we could just confine the new flat bottom'er to the river.

Conclusion: Maybe the Alumacraft flat bottom jon, 1442 NCS.

Just wish I could find a 1448 NCS Alumacraft riveted, that's be my dream boat I think.

Am I on the right track?

 

[overboard]

Your best bet for shallow water would be to run a jet.
I think a 1448 with a jet would be a good bet.
I really don't think you would have a problem with a 16' boat with a jet.
We have a very shallow river here in Pa., the Susquehanna. Almost all the guys that fish it run jets.
I would assume most replys will also say: skinny water=jet motor. That's what they're made for.

 

[MrSimon]

16 vs 14 won't make a difference in draft. Get a 16 if you can. Wider is better.

Pretty much any well balanced jon boat (flat front or mod v) will float in a foot of water or even less. Sometimes as little as 6".

Like was said above, the motor is what makes all the difference. If you are in that shallow of water, get a jet. There is no way on God's green Earth that you can run a prop in a rocky shallow river .... at least without spending a lot of time drifting with the motor tilted up out of the water.

I fish the Susquehanna a lot, and I've done it with a lot of different boats. I've used a 1448, a 1648, a 1436, and even a shallow v hull. They all worked about the same, but after patching holes and pounding out dents for five years, I now use a canoe and couldn't be happier!!!

 

[dsuden]

OK, let's talk about jets. How small can you go with a jet rig (14' for example?), and does it require a tunnel hull? How low horsepower can you get? I would assume you need more horsepower per MPH than you'd get with a prop, right?

Suppose I wanted to do a little jet rig, 14' or 16', with the lowest horsepower possible. What kind of money would we be looking at?

Thanks, appreciate the insights...

 

[MrSimon]

I can't answer all your questions, but here is what I do know.

You don't need a tunnel hull. A regular mod-v jon boat seems to be the hull of choice for jet rigs.

14' with a jet would be just fine. 16' is preferred just due to the extra space, but if you don't need/want the space, 14 is just fine.

Jets produce something like 20% less power than a prop motor of the same HP.

I think I've seen 25HP jets ..... don't think I've ever seen a 9.9 jet .... they typically are in the 40-90 range on the river around here.

 

[JoshKeller]

dsuden » Yesterday, 09:26[/url]"]We live on a river with a lot of shallow spots, which become more "plentiful" as the summer wears on. We need a shallow-runner. I tried out a Triton 16' mod vee with decking and a 25 HP engine, welded, probably .01 gauge aluminum, and it had too much of a draft; the lower tip of the prop fin was probably at least two feet below the water.

Back to the drawing board!

As it stands now, my guess is that we should probably go with a flat bottom, lighter gauge aluminum, riveted, and as wide as possible for more buoyancy. I'm gun-shy now about a 16' length. Maybe 14' would be lighter, thus less draft. Would translate into less demand for horsepower too, which would result in a lighter motor, less tail drag. We have another boat we can use for lakes and "wavy situations," so we could just confine the new flat bottom'er to the river.

Conclusion: Maybe the Alumacraft flat bottom jon, 1442 NCS.

Just wish I could find a 1448 NCS Alumacraft riveted, that's be my dream boat I think.

Am I on the right track?

i bought my alumacraft 1648 from these guys and they had plenty in stock...

https://edsmarinesuperstore.com/jon_boats.htm

 

[dsuden]

The 1648 mv does really appeal to me. It's no-center-seat which I prefer. Suppose I put a 9.9 HP on the back of it. Would it ride pretty high in the water when going slowly? It's all about draft for me, and I'm going to be stuck with a prop (rather than a jet) due to cost. The fewer inches we go below the surface, the better.

So 1648 and a 9.9...a pretty good bet?

 

[JMichael]

Are you looking at 4 stroke or 2 stroke motors? I don't know the difference on the 4 stroke models but for the 2 stroke, the 9.9 and 15 hp motors weigh the same and the 9.9 may not be able to get that boat up on plane depending on your load. And if you're really looking to keep the draft down, you might want to consider adding a set of sponsons to the back end of your boat.

 

[dsuden]

It'll be a four-stroke.

 

[MrSimon]

How fast do you need to go?

There are some really light weight, but low HP, motors out there that wouldn't drop the rear of your boat at all. Granted, they won't plane you out ... but they won't stick your bow way up in the air either.

Max speed would be around 5mph.

 

[cva34]

Just a point some people miss..when talking draft..The diff between MV and Flat B..as far as how far the prop and skag stick down below bottem of boat..They stick down about same one :MV cavatation plate set at bottem of V....Flat b..cavatation plate is set a bottem of flat bottem (average set up)....clear as mud i hope clearer...cva34

 

[erictetterton]

my local Alumacraft dealer has the 1448 NCS. Find the Alumacraft dealer near you and they can order that boat for you. It will only take a few weeks for them to get it.

 

[dsuden]

Thanks for all the insights, guys. Ultimately I found a Mirrocraft riveted 1448 mv with no center seat just down the road and it looks perfect. Bought it and brought it home today.

I'll start a topic on this so I can blog the entire experience, including installing lights, bilge, battery, wires, etc., motors, etc. Will include some pictures as I go along.