# Sea trail!! Boat nose diving!!



## Brett (Jul 16, 2008)

Need to see a picture of the engine on the transom. (from the side)
Sounds like a combination of factors contributing to the problem.
But most likely, too much weight forward and engine trimmed too far in.

http://books.google.com/books?id=YpMTd7-Mb3sC&pg=PA100&lpg=PA100&dq=boats+what+causes+plowing&source=bl&ots=wQcyrjSo7w&sig=LdJ0k2vDJAO6euVYWH3WL2Np174&hl=en&ei=6IirTbPwDMLY0QG6wfX4CA&sa=X&oi=book_result&ct=result&resnum=2&ved=0CBcQ6AEwAQ#v=onepage&q&f=false


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## travis_smith (Apr 2, 2011)

Ok. The fin on the bottom of the engine is level with the bottom of the boat. i put a angle level on the bottom of the boat and it was level. 
As for weight, the only thing up front is the anchor. All other weight is in the back (gas tank, gear, me, etc) lol

And ill try and get the picture.


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## Brett (Jul 16, 2008)

Get a picture from the side of the boat also, showing the profile.
Need to check the hull shape, at keel, chine and sheer.
A seriously hogged hull will plow badly also.


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## travis_smith (Apr 2, 2011)

What do you mean by a hogged hull?


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## Brett (Jul 16, 2008)

Hogging is when the line of the keel bends upwards,
often caused by an improperly set up trailer
or storing a small hull inverted, without sufficient supports.


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## topnative2 (Feb 22, 2009)

possible solutions

1. motor height on transom
2. may need to shim mounting bracket to vertical
3. cup the prop raises the bow

and hope it is not what B. is asking about [smiley=1-headache.gif]


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## travis_smith (Apr 2, 2011)

My transom height is 17 inches. If i'm in the boat by myself, I can raise the pin to the top hole and the boat runs fine. If I put another person in it then it starts to nose dive.  what should my transom height be? Thanks guys


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## travis_smith (Apr 2, 2011)




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## travis_smith (Apr 2, 2011)

.


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## Brett (Jul 16, 2008)

Engine height and angle look ok.
Nothing visibly wrong from the bow shot.

Could it be that the outboard is just too "tired" to push the load? :-?


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## travis_smith (Apr 2, 2011)

I had it on a 16ftfiberglass boat and it pushed it great.


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## topnative2 (Feb 22, 2009)

go up a notch on the mounting and see what happens

also, get a10' straight edge and place it against the keel--centerline---- and see if there is a "hook" in the hull
are u having fun yet?


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## travis_smith (Apr 2, 2011)

What do u mean a hook? like sagging or the hull sagging upward(hogging)?


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## topnative2 (Feb 22, 2009)

exactly. 
if the bow is being pushed down it usually means the motor trim is not adjusted correctly or it is mounted to low--meaning to much lower unit in the water
if u have a hook in the hull ouch! no clue how to fix it if it is even possible.
transom height on a small boat usually requires a 20" or a 15" lower unit
me thinks jacking the motor up an inch is a place to start but make sure ur getting water to the intake
Brett is the encyclopedia for us on this site


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## WhiteDog70810 (May 6, 2008)

Hook is the same as hog  While they are often used interchangeably, hook is usually thought of as being limited to the last few feet of planing surface while hog usually means the entire planing surface is caved in.  Hog is always an unintentional thing due to poor storage or bad construction.  Some manufacturers intentionally incorporate hook into the last half of the planing surface in order to improve trim.  Both are most commonly due to poor trailer set up, being stored upside down or on the ground, as Brett said +/- being stored outside full of rain water and exposed to the sun.  A pic of your entire keel from the cut water looking back toward the stern is the best way to show us whether you hull has either issue. 

Your transom height is what it is.  Since your cav plate is reasonable close to the bottom edge, your motor is the correct shaft length.  

It plows when the pin is low and it porpoises when the pin one higher?  What you are describing is pretty drastic for a single pin hole difference in angle.  First and foremost, what do you describe as nose diving?  A vee-hull will have more contact with the water farther forward than a semi-vee, mod-vee or flat bottom hull and will plow through chop instead of bouncing over it.  If you are used to one of the latter hull types, a true vee-hull might feel really "wrong" to you even though it is doing what it is designed to do.

An overpowered hull might act like this also at full throttle, but a 14' Vee-hull shouldn't have a problem with a 25 HP.  What does your rating plate say?  

You will probably correct this oversensitivity by adjusting the balance of the hull.  I would go out by yourself and move you load around the hull until it is "right".  Where are your batteries and fuel?  If both are in front, you may have to move one or the other to the stern.  If everything is already in the back, I'll bet your hull is hogged.

If you have a hook or hog, your hull will be more sensitive to weight in the bow than your previous boat.  You have to figure out how to live with the plowing because fixing them is not usually cost effective.  You may need a setback motor bracket and some trim tabs to live with them, but don't worry about that until the easy answers are eliminated.

Don't worry, you'll get it figured out.

Nate


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## travis_smith (Apr 2, 2011)

My fuel tank is up front. No battery. no live well


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## travis_smith (Apr 2, 2011)

and im discribing nose diving as water almost coming over the bow and the boat going uncontrolable


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## topnative2 (Feb 22, 2009)

reviewing ur pics. and descrips.>
I would move the motor higher 1-2 inches and distribute the weight and see if it helps----the boat sits lower and at more of an angle w/ all the weight in back.
If u see improvement but the motor is to high and u get "blow out" in a turn- lower it a lil. If the problem is still there then shim the mounting bracket(between the hull and bracket) till u get a true vertical w/ the boat sitting in the water.

My money is on raising the motor up to where the cavitation plate is at least 1" above the bottom.

I am assuming you are having this problem in realitivly
calm water and not while your going over waves and serious wakes. Just making sure.


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## TomFL (Oct 2, 2007)

> Hogging is when the line of the keel bends upwards,
> often caused by an improperly set up trailer
> or storing a small hull inverted, without sufficient supports.


Brett, we have different opinions of hogging. Where I come from the above is called a "hook".....

And this is called hogging:










*Disclaimer: That's not my wedding photo nor my sister, and I didn't make the typo on the photo......


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## AfterHours2 (Aug 2, 2010)

I had the same problem with a fiberglass skiff a long time ago and it ended up being that the hull was allowing water to reach in the areas it shouldn't have been and it was fully logged. Thats the only logic I have for you. If it is/has been stored outside uncovered for a some time then start searching.. Good luck...


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## topnative2 (Feb 22, 2009)

good point-water shifting inside the hull- never thought of it geez! 
I am so in the "box" sometimes
Halp!!!!!!!!!!!!!!!!!!!! ;D


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## topnative2 (Feb 22, 2009)

spoke w/ a friend who used to be a test driver for OMC in stuart he stated: look at the spray COMING OFF THE MOTOR WHEN UR RUNNING AND IF U HAVE a lot of spray then the motor is mounted to low for sure but he still advises to raise the motor up by an inch at a time to take care of the problem-----assuming no H2O problem


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## travis_smith (Apr 2, 2011)

I originally was gonna put a 20 inch shaft engine on it so i lowered it from 18 to 17. When it was 18 it wouldnt get upon plane at all.


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