boat nose dives badly

bayougrande · 06-09-2008, 01:23 PM

aight this is what i got

16ft v bottom boat w/ 90hp evinrude 20"shaft motor.

i can run the boat fine up to 25-30- mph depending of which way i'm running into the wind. and i have plenty of throttle left. but when i give it just a hair more throttle the nose dives extremley bad no matter how far i trim the motor. I've heard from a couple people that some boats are built with a "hook" in the back of the hull. If this is true how can i get my boat to run like i need it to?

thanks

Speckulator · 06-09-2008, 01:33 PM

Please explain!!!! Front end bounces up and down? Boat's tryin to submarine? Need more info.

George

BIGRIGZ · 06-09-2008, 01:38 PM

never heard of a hook.

Is the trim switch hooked up backwards or being used opposite of what it's supposed to?

Buckyt · 06-09-2008, 05:13 PM

Some boats can develop a "hook" if they don't fit the trailer properly. ie. if they hang over the back of the trailer supports and have a heavy motor left on the transom. A lot depends on the type of boat, aluminum, fiberglass, age, etc. You can check this by placing a straight board on the bottom of the boat spanning from the transom forward. If there is a hook, there will be a space between the board and the bottom of the boat.

This can cause the boat to nose dive depending on the severity of the hook.

Do you have a add on planing fin installed? If so, this can be a problem if not installed properly.

Tuna Man · 06-09-2008, 05:27 PM

A hook in a hull will/can cause the hull to act like a suction cup on the water. Hooks can also be caused by hitting something, thus putting a dent in the hull, be it fiberglass, or metal. Opposite of a hook is a rocker, and effects are opposite.

off route II · 06-09-2008, 05:53 PM

Quote:

Tuna Man (6/9/2008)A hook in a hull will/can cause the hull to act like a suction cup on the water. Hooks can also be caused by hitting something, thus putting a dent in the hull, be it fiberglass, or metal. Opposite of a hook is a rocker, and effects are opposite.

years ago my dad bought a boat (early fiberglass days) that had a hook in the bottom. we had to keep a big bag of sand in the bow to kep it from beat'in you to death.

DOUBLE "D" & LV · 06-09-2008, 07:13 PM

What is your boat made of? You need to inspect the hull and determine what is causing it. Depending on what your boat is made of, then there are different things to do to fix the problem. The other aspect of this may be the engine height.

X-Shark · 06-09-2008, 09:07 PM

For the most part a hook will act like a trim tab in the down position. Thus pushing the Bow down, even if you trim the motor out.

bayougrande · 06-09-2008, 09:42 PM

the boats fiberglass and it sits with six inches of trailer bunks past the transom(but i don't know if it did ever sit on a trailer for a long time) and that is what i was told could most likely be the problem . since the boat is an 86 but it's not soft anywhere and i ran a board down the bottom and no gap. I've also heard from an old wise man that used to drag race boats that said he used to sand the hook out of a boat to make it reach top speeds. does anyone know how to do this and another idea i have is if i lower the motor farther than it needs to be would that help. It sits in the right postions now. I also tried taking the dolf-fins off the motor to see if that was making the nose dive and itdidn't change it a bit.

wld1985 · 06-09-2008, 09:53 PM

I'm with what was said a few post up.... It could possibly be your motor height.. How far past the boat does your motor sit???

06-09-2008, 01:23 PM	#1
bayougrande Senior Member Snapper Join Date: Oct 2007 Location: perdido key, fl. Posts: 425	boat nose dives badly aight this is what i got 16ft v bottom boat w/ 90hp evinrude 20"shaft motor. i can run the boat fine up to 25-30- mph depending of which way i'm running into the wind. and i have plenty of throttle left. but when i give it just a hair more throttle the nose dives extremley bad no matter how far i trim the motor. I've heard from a couple people that some boats are built with a "hook" in the back of the hull. If this is true how can i get my boat to run like i need it to? thanks

06-09-2008, 01:33 PM	#2
Speckulator Senior Member Snapper Join Date: Oct 2007 Posts: 591	RE: boat nose dives badly Please explain!!!! Front end bounces up and down? Boat's tryin to submarine? Need more info. George

06-09-2008, 01:38 PM	#3
BIGRIGZ Senior Member Grouper Join Date: Oct 2007 Location: Pace / Milton Posts: 794	RE: boat nose dives badly never heard of a hook. Is the trim switch hooked up backwards or being used opposite of what it's supposed to?

06-09-2008, 05:13 PM	#4
Buckyt Senior Member Grouper Join Date: Oct 2007 Posts: 774	RE: boat nose dives badly Some boats can develop a "hook" if they don't fit the trailer properly. ie. if they hang over the back of the trailer supports and have a heavy motor left on the transom. A lot depends on the type of boat, aluminum, fiberglass, age, etc. You can check this by placing a straight board on the bottom of the boat spanning from the transom forward. If there is a hook, there will be a space between the board and the bottom of the boat. This can cause the boat to nose dive depending on the severity of the hook. Do you have a add on planing fin installed? If so, this can be a problem if not installed properly.

06-09-2008, 05:27 PM	#5
Tuna Man Senior Member Grand Slam Join Date: Oct 2007 Location: Calera, AL....25 Miles S of Birmingham Posts: 6,583	RE: boat nose dives badly A hook in a hull will/can cause the hull to act like a suction cup on the water. Hooks can also be caused by hitting something, thus putting a dent in the hull, be it fiberglass, or metal. Opposite of a hook is a rocker, and effects are opposite.

06-09-2008, 07:13 PM	#7
DOUBLE "D" & LV Senior Member Grouper Join Date: Oct 2007 Location: pensacola Posts: 863	RE: boat nose dives badly What is your boat made of? You need to inspect the hull and determine what is causing it. Depending on what your boat is made of, then there are different things to do to fix the problem. The other aspect of this may be the engine height.

06-09-2008, 09:07 PM	#8
X-Shark Senior Member White Marlin Join Date: Oct 2007 Location: Pensacola, Fl. Posts: 3,031	RE: boat nose dives badly For the most part a hook will act like a trim tab in the down position. Thus pushing the Bow down, even if you trim the motor out.

06-09-2008, 09:42 PM	#9
bayougrande Senior Member Snapper Join Date: Oct 2007 Location: perdido key, fl. Posts: 425	RE: boat nose dives badly the boats fiberglass and it sits with six inches of trailer bunks past the transom(but i don't know if it did ever sit on a trailer for a long time) and that is what i was told could most likely be the problem . since the boat is an 86 but it's not soft anywhere and i ran a board down the bottom and no gap. I've also heard from an old wise man that used to drag race boats that said he used to sand the hook out of a boat to make it reach top speeds. does anyone know how to do this and another idea i have is if i lower the motor farther than it needs to be would that help. It sits in the right postions now. I also tried taking the dolf-fins off the motor to see if that was making the nose dive and itdidn't change it a bit.

06-09-2008, 09:53 PM	#10
wld1985 Senior Member White Marlin Join Date: Oct 2007 Location: Pensacola Posts: 3,586	RE: boat nose dives badly I'm with what was said a few post up.... It could possibly be your motor height.. How far past the boat does your motor sit???

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