# Help needed. Running shallow in Pathfinder 15T



## h_10 (Jul 10, 2011)

here's a pic of the back of the boat.


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## anytide (Jul 30, 2009)

how far back is the prop from hull ?
how far up from top o tunnel to cav plate?
motor has plenty of power?
you'll leave mud trail in 12" of water whether prop touching or not
what pitch / hull weight ?
set up right it will hole shot in 24" easy , but will also mud trail from thrust
-anytide


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## lemaymiami (Feb 9, 2007)

At a glance it looks as though your motor is set a bit low, raise it one notch at a time while testing to make sure you're still picking up water for cooling, etc.  When you can't keep from blowing out (basically losing the "bite" your prop should have) when turning, then you're too high and need to drop it back down one bolt hole...  Remember that the tunnel should allow you to run your motor higher than it would be on a conventional hull, you have to figure out how much higher without burning it up, etc.  

Next, burning a trail across the flat isn't a good idea at all (not good for motor, or the flat, or the fish that live there).  Always try to run in enough water where you're not grinding the bottom.  Down at Flamingo we now have pole and troll zones just because of folks cutting trails across the flats....and very badly scarring areas that should not have one prop mark anywhere.

Lastly, tunnel hulls don't behave like regular hulls... Trying to jump up on plane the way you would with a conventional hull using a tunnel hull just won't work very well....  I have a good friend who operates a tunnel hull in very shallow water.  He taught me to accelerate slowly in a tunnel.  Just get it idling in forward then gradually add throttle and the thing will rise slowly and just transition from barely moving to up on plane -- All without squatting or needing to "jump" or anything.  The whole procedure takes some getting used to... 

One other item... once you sort out that tunnel hull and getting it running properly - get a stainless steel prop for it.  You'll be glad you did.


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## tom_in_orl (Dec 9, 2006)

I don't have any experience with tunnel hulls so take my comments with a grain of salt. Maybe someone here can point out where my input is valid on a traditional hull vs. a tunnel hull. 

First off your prop doesn't look like a good choice for your application. It appears to be a standard aluminum prop. Thats fine for pushing a normal boat but you are trying to optimize your set up. You are going to need something that minimizes cavitation and has good bite when set up to run shallow. Most shallow running boats like yours are running 4 blade props with some cupping.  Here is an example

PowerTech SRA4

Second, You may want to remove the doel fin (cavitation plate accessory) as you begin optimizing your set up. The reason I think this may be important for you is that you mentioned issues in 18" - 24" of water. That boat should be able to run in let than 1' with out every touching bottom if set up correctly. One of two things may be happening. You may not be getting all the way on plane. That could be due to boat weight, motor issues. or something else. The other possible problem that may be contributing is the doel fin digging into the water for some reason. Once you have everything else set up and working then add the doel fin back on the boat and see if you can optimize it further. 

Good luck. Let us know what resolves your issues.


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## h_10 (Jul 10, 2011)

thanks for the responses. i'll mess w/ the engine settings to move it up higher. also will be looking into a four blade prop. also getting some smart trim tabs. hopefully all of the above will allow me to properly run shallow.


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## TomFL (Oct 2, 2007)

Engine looks a bit low, here's my old 17t setup:


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## swaddict (Dec 19, 2009)

Can't tell if the motor is low or just the angle of the photo, but I have the 17T and can add the following.  Trim tabs will help, you'll be able to run shallower with the use of tabs. Try starting with the engine trimmed all the way down.  Roll on the throttle and you should pop up on plane.  Then experiment with starting with the engine trimmed higher, you'll find the spot where the prop will not bite anymore.


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## bw510 (Sep 1, 2011)

I agree with trim tabs but invest in real ones that you can adjust. With tabs down and motor down you can launch in a hole and trim motor up without the front rising and keeping you more clear of the bottom when it gets skinny.


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## paint it black (Nov 3, 2007)

Tabs down, trim up. 
Most tunnels I see are sporting four blade props.


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## SilentHunter (Jun 14, 2010)

tabs for sure.

4 blade cupped ss prop and get rid of the dolfin they are useless on that boat.


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## fsae99 (Apr 8, 2010)

You might want to weigh that boat. What is the draft at rest? 
If there is no weight issue and it is manual trim then move the pin down one hole. 
If power TNT then trim all the way down to launch and trim up some to run. 

Given the wear line on that prop and the skeg is almost worn away, I say you are dragging through the mud. Not good.

Very few boats do not benefit from tabs. Sounds like yours would. Tabs down to take off. Also there is the spin plane move. Turn it all the way left and roll on the gas and when about 150 degrees straight the motor out. 

However, I think something else is going on with your boat. Over weight, motor not making rate HP, Prop is shot or weight distributed all in the rear.


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## TomFL (Oct 2, 2007)

Listen to the above posters. 

That hull needs tabs! A good, fast-acting set of lenco's. 

And a 4-blade prop!

-T


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## HighSide25 (May 15, 2007)

All lencos are the same speed, they do not make a "hi speed" actuator.

Just fyi so you dont go out searching for it.


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## h_10 (Jul 10, 2011)

again, you've given much to consider. problem is this is my first boat and i've only had it for 3 weeks. the condition of the skeg and prop is how i received them. 

so from what i've read.

- remove doel fin
- get a 4 blade ss prop like the one linked above
- adjust the motor setting a few pins to set the prop to sit higher
- check engine for compression and hp
- trim tabs, i assume smart tabs work just as well as lenco hydraulic?

your responses is what makes this forum the awesomeness that it is.


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## paint it black (Nov 3, 2007)

> again, you've given much to consider.  problem is this is my first boat and i've only had it for 3 weeks.  the condition of the skeg and prop is how i received them.
> 
> so from what i've read.
> 
> ...



no, smart tabs won't work. you want tabs that you can adjust. don't go hydraulic, go with actuators. 
you want to be able to pin the tabs down while running shallow. To keep the back end of the skiff up while trimming the motor up. Otherwise, the bow would go up, causing the back end to go lower in the water, hitting bottom. 

I don't know, maybe there's different technique when running an outboard with no power trim n tilt.


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## h_10 (Jul 10, 2011)

smart tabs have actuators.

http://www.nauticusinc.com/smart_tabs.htm

or 

http://www.nauticusinc.com/smart_tabsSX.htm

these should work, correct?

and my motor does have power tilt.


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## HighSide25 (May 15, 2007)

no, smart tabs have high pressure springs, kind of like the fork shocks on a bicycle. when you go fast and they get more upwards pressure, they go up. you need lencos or bennets. bennets are electric/hydrolic and lencos are electric.... most of us probably have lencos, i do and LOVE THEM


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## swaddict (Dec 19, 2009)

With that hull it will depend on which 4 blade prop you choose (powertech), which will determine how high you can raise the motor. 

Another thought, I'm assuming that your boat is a tiller. Which would put your weight (and possibly passenger), along with battery and motor all placed on the back end of the boat. Try filling the fuel tank up and placing a couple batteries (or something with similar weight) in the front hatch. This should level your boat out and not feeling like your dragging. You do not necessarily need a 4 blade with that hull. It seems that it's a little of everything, on the bottom end of horse power, find a good 4 or 3 blade prop, readjust weight in boat and lenco trim tabs.


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## DuckNut (Apr 3, 2009)

> The prop starts digging in and leaves a bad mud trail


Keep ripping the bottom and your prop and skeg will get wore down even more and therefore less draft...heck you're already half way there.

Big tickets to people who do that in certain areas. Certain - should be all.

Look at TomFL's and use that as an example. His jumped up on plane in 1 "one" boat length. If you are dragging bottom in two feet of water - I suggest ignoring what these guys are telling you and take the boat to a professional. Something is seriously wrong and by you trying to figure it out one piece at a time will cost you twice what a pro would cost.

Something is really wrong- you have a great boat - go seek professional help.


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## h_10 (Jul 10, 2011)

"go seek professional help"

we're still talking about the boat, right?


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## makin moves (Mar 20, 2010)

where are you located, maybee someone here on the forum can take a look at it if you live in there area


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## TomFL (Oct 2, 2007)

I ran a 17t for a while, and I know it's different than the 15t, but when you get your setup right, I would think it should be able to get on plane in less than 1 boat length, with absolutely no squat in the rear. It should just move forward and up, never squatting. 

Trim tabs were a MUST on my 17t, not only for getting up on plane instantly, but also because that hull had a tendency to run on one sponson or the other, very weird. The tabs were always being tweaked to get the hull to ride level side-to-side, and if someone shifted their seating position you had to make small adjustments to the tabs again. 

-T


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## h_10 (Jul 10, 2011)

i'm in austin, tx but could take my boat to anywhere along the coast from galveston to corpus. that was going to be my next question. are there any recommendations for mechanics in texas familiar w/ the workings of a 15T?


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## Brett (Jul 16, 2008)

Find one who has worked on a Texas Scooter.
Same concept, different brand of boat.
They're tunnel hulls that require a similar setup.


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## scottsflyshop (Oct 2, 2011)

I ran a 15T tiller for three or four years. It had a 40hp Merc on the back and no tabs. With that setup, I had to use the tilt/trim a good bit. You'd bump the motor up a touch and ease in the throttle to get going and then slowly lower the motor down. I kept two coolers in the boat for seats/storage. If I was alone, I'd put the heavy one up front and the boat ran great and super skinny. With another passenger, you took your time getting up on plane or had the person sit up further up for a bit.

In the end, a set of tabs probably would have been worth the money but I liked the boat for what it was, simple. In your situation, I'd raise the motor a touch and not be in a hurry to get on plane.


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