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Tunnel hull aluminum jon boat?

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Found a good deal on a used tunnel hull aluminum jon boat, but I dont really need a tunnel hull, what if I just mount the outboard at a regular depth - would my performance be the same as a regular jon?

 

Also the transom on this boats specs is 15" - which I believe is standard, why wouldnt a tunnel hull not have a higher transom so that the prop is higher and in the tunnel area?

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IIRC, 15" is a short shaft, 20" is a standard, 24" is a long shaft.  If it is calling for a 15" then i'd bet the prop will be in the right place.

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43 minutes ago, redmexican5081 said:

IIRC, 15" is a short shaft, 20" is a standard, 24" is a long shaft.  If it is calling for a 15" then i'd bet the prop will be in the right place.

Thanks, you mean "right" as in at regular depth and not high up in the tunnel area where performance will be hurt?

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Without the actual boat information I can't give you a definite answer.  The center of the prop shaft should land at about the depth of the hull. This only leaves the skeg below the hull and puts the motor up into the tunnel whereas on a standard hull the anti vent plate is about even with the hull and the prop shaft is 3" below the hull 

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To take full advantage of a tunnel hull, you need a hydraulic jack plate.  That way you can drop the motor down to get on plane and then raise it up to take advantage of being able to run shallow.  When I say shallow, that's a few inches of water on full plane.   Great for rivers with sandbars and lots of trees etc. in the water or back bay flats.

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4 hours ago, rustybass said:

Found a good deal on a used tunnel hull aluminum jon boat, but I dont really need a tunnel hull, what if I just mount the outboard at a regular depth - would my performance be the same as a regular jon?

 

Also the transom on this boats specs is 15" - which I believe is standard, why wouldnt a tunnel hull not have a higher transom so that the prop is higher and in the tunnel area?

 

I'm running a Alweld 1652VV Marsh Tunnel with a Tohatsu 40 hp 4-stroke.

 

Most midrange outboards no longer come with clamps to hold the motor flat on the transom. Instead they are through bolted at the optimal height. Mine is set with anti vent plate 1.25" above the hull. 

 

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When I think of a racing tunnel hull the centerline surface is above the the tunnel planing surfaces, the center surface running dry on plane, lifting hull higher out of the water.

Most jon boats with tunnels have a traditional flat bottom center line surface to 2 slightly raised tunnels about 1/2" high by 8"-10" wide to reduce surface drag when the boat is on plane. Outboard engine height is unaffected by the Jon boats recessed tunnels because the boat still planes on it's centerline flat hull surface.

Tom

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1 hour ago, WRB said:

Most jon boats with tunnels have a traditional flat bottom center line surface to 2 slightly raised tunnels about 1/2" high by 8"-10" wide to reduce surface drag when the boat is on plane. Outboard engine height is unaffected by the Jon boats recessed tunnels because the boat still planes on it's centerline flat hull surface.

Tom

 

Aint been around Jon boats lately?

 

Most tunnel hull Jon boat have modified vee hulls.

 

Tunnel hulls are not only for running in extremely shallow water but for getting up on plane in extremely shallow water. 

 

The tunnel on my boat is 3 1/2" high, 14" wide, & about 36" long.

 

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1 hour ago, Catt said:

 

Aint been around Jon boats lately?

 

Most tunnel hull Jon boat have modified vee hulls.

 

Tunnel hulls are not only for running in extremely shallow water but for getting up on plane in extremely shallow water. 

 

The tunnel on my boat is 3 1/2" high, 14" wide, & about 36" long.

 

To me a modified V aluminum (Tracker ) style are bass boats, Jon boats being square bow flat bottom boats. I haven't seen a Jon boat where I fish in a decade, Tracker style bass boats are common. 3 1/2" deep is a serious tunnel!

Tom

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1 hour ago, WRB said:

Jon boats being square bow flat bottom boats. I haven't seen a Jon boat where I fish in a decade, 

 

 

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On 6/7/2019 at 8:36 PM, WRB said:

To me a modified V aluminum (Tracker ) style are bass boats, Jon boats being square bow flat bottom boats. I haven't seen a Jon boat where I fish in a decade, Tracker style bass boats are common. 3 1/2" deep is a serious tunnel!

Tom

 

There seems to be a lot of mixing of wording; tracker calls their Modified-V boats "Jon" boats, - other manufactures call them Modified-V boats instead.

 

On 6/7/2019 at 1:13 PM, redmexican5081 said:

Without the actual boat information I can't give you a definite answer.  The center of the prop shaft should land at about the depth of the hull. This only leaves the skeg below the hull and puts the motor up into the tunnel whereas on a standard hull the anti vent plate is about even with the hull and the prop shaft is 3" below the hull 

 

The transom is standard 15", so is the tunnel simply meant to allow more water for the prop so you get on plane easier in shallow water? I don't see how it would allow you to run in shallower water with that transom.

 

 

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18 hours ago, rustybass said:

The transom is standard 15", so is the tunnel simply meant to allow more water for the prop so you get on plane easier in shallow water? I don't see how it would allow you to run in shallower water with that transom

 

The tunnel is "supposed" to allow you to get on plane easier & run in shallower water. How much it actually works is up to debate.

 

As @Way2slow started a hydraulic jack plate makes a huge difference, without one I aint to sure. What helped my boat was adding Nauticus Smart Tabs!

 

IMG_20190609_064332.jpg

smart_tab_black_9.jpg.64202c7eb67918f9fc311860441ca675.jpg

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48 minutes ago, Catt said:

 

The tunnel is "supposed" to allow you to get on plane easier & run in shallower water. How much it actually works is up to debate.

 

As @Way2slow started a hydraulic jack plate makes a huge difference, without one I aint to sure. What helped my boat was adding Nauticus Smart Tabs!

 

IMG_20190609_064332.jpg

smart_tab_black_9.jpg.64202c7eb67918f9fc311860441ca675.jpg

Is that the boat Ott Defoe won the Open with? Super nice.

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32 minutes ago, flatcreek said:

Is that the boat Ott Defoe won the Open with? Super nice.

 

Yeah 😉

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Many of the tunnel hulls were built to aid with outboards running water jet lower units. The water is directed along the bottom and up towards the jet's intake screen.  This is definitely a benefit when running shallow rivers.

 

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I would use the tunnel hull as it is designed to be able to run shallower.  They were designed to be used with jet drives and allow for super shallow runs on plane.  

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3 hours ago, flyfisher said:

They were designed to be used with jet drives and allow for super shallow runs on plane.  

 

Interesting since tunnel hulls were designed long before jet drives.

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1 hour ago, Catt said:

 

Interesting since tunnel hulls were designed long before jet drives.

this is true but now I have seen a lot more tunnel drives utilizing an outboard jet motor than a conventional but my experience is mostly seeing boats designed for river running.

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11 hours ago, Catt said:

 

The tunnel is "supposed" to allow you to get on plane easier & run in shallower water. How much it actually works is up to debate.

 

As @Way2slow started a hydraulic jack plate makes a huge difference, without one I aint to sure. What helped my boat was adding Nauticus Smart Tabs!

 

 

Okay that makes sense, I guess if Im running the engine at the standard depth with 15" transom then I cant see how the tunnel is going to really hurt performance that much? and you could even add a jack plate at some point and run real shallow, so seems like the tunnel wont hurt to have.

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3 hours ago, flyfisher said:

this is true but now I have seen a lot more tunnel drives utilizing an outboard jet motor than a conventional but my experience is mostly seeing boats designed for river running.

 

See that's the difference I live in Southwest Louisiana & you will not find a jet drive unless it on a Jet Ski!

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46 minutes ago, Catt said:

 

See that's the difference I live in Southwest Louisiana & you will not find a jet drive unless it on a Jet Ski!

yeah if you go up on the susquehanna or middle/upper james just about any boat you see running will be a jet boat and a lot are even inboard jets.  My dad just sold his inboard jet and that thing was amazing really.  It would draft deeper than it needed to run.  He got stuck more than a few times at first because he was scared to just let it rip over the shallows and he would slow down and get beached basically.  Then he just went with it and it was all good....crazy to be going 50+ in under a foot of water.

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1 hour ago, flyfisher said:

crazy to be going 50+ in under a foot of water.

 

Try going 50 through a marsh boat trail that's barely as wide as your 52" hull with reeds on both side taller than you!

 

Of all the boats I've driven shallow water makes me 😂

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The Susquehanna River is where I ran a jet back before the factories sold them. You purchased the jet lower unit from Outboard Specialties and installed it yourself. That was in the mid 80's. Suzuki sold the first ones I remember seeing. If I wanted to cross McKees Half Falls it was either a jet of one of Snyder's Airboats. I lived minutes from where the Juniata and Susqy came together. My boat was not a tunnel hull, so I ran a manual jackplate on my boat. Ityhad a 50 hp Merc on it.

 

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