Tech Definition

Sea Rider

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If porpoising is when boat alternately rises and submerges bow, what do you call when a boat plunges bow to sea and rocks sideways ? it's difficult to control at speed, has erratical water behaviour, no matter if trim and weight ballance are set spot on. Meantime just good for fast displacements boring speeds.

Happy Boating
 
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Faztbullet

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Mar 2, 2008
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If bow runs deep at WOT its called plowing and engine trim or tilt pin need to be extended out. The only problem with this is it can cause slow planning and porpoise at mid rage speeds.
 

gm280

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The side to side rocking sounds more like "chin walking". My boat had that extremely bad before I raised the engine and that not only stopped the chin walk, but also allowed a much higher safe top speed as well. Before I lifted the engine, when I would get to about 50 MPH it would start chin walking and would nearly throw you out of the boat if you didn't back off. After raising the engine I topped out a 63 MPH and smooth as silk...on select slight chopped water. I don't know if you are talking about chin walk but that is the side to side rocking that plagued my boat...
 

alldodge

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If porpoising is when boat alternately rises and submerges bow, what do you call when a boat plunges bow to sea and rocks sideways ? it's difficult to control at speed, has erratical water behaviour, no matter if trim and weight ballance are set spot on. Meantime just good for fast displacements boring speeds.

Happy Boating

Are you talking about chine walking? With chine walking the bow is not really in the water it it starts going side to side at high speeds
 

Chris1956

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Mar 25, 2004
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If the wind or waves are behind you, it could be "pitch-polling". We have that when the wind is against the tide in the inlet. The waves stand up, and if the waves are behind you, you can stuff the bow and be pushed sideways. You can broach, if you are not careful.
 

steelespike

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If your talking about a really flat attack angle with the bow in the water and self steering we have plowing and bow steering going on.
Either the trim is down too far or the hull is compromised. With a hook near the transom.
Usually doesn't respond to up trim.
 

Sea Rider

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Sorry folks, important data was missing. It's a 4.30 mt Seamax alum floor inflatable powered by a 2 stroke Tohatsu 30 HP which is the max can handle.

-Water flow at speed is passing right under small water deflector plate, ideal height for an inflatable.

-The inflatable bow seems to be too near towards bow, there's water splashes side of bow no matter if an adult or light feather champ sits there.

Trim is spot on, if moved from second hole to first or third hole water performance gets worst. Second is ideal.

-Tubes and keel are inflated to it's max 3.5 psi working pressure.

-Been tested with just 3 adults, that inflatable can carry 7 passengers, engine is undergoing its break in period, the boat planes at 1/3 throttle, at 1/2 throttle the performance is scarry, chine walks like cracy.

-Seems this model is a crappy one, just good for lakes, ponds, rivers, pools, as diving platform, fishing, sipping bears, you name it. Incredible plate bears a Canadian Certifcate. Very near to be returned to dealer along consequent anger...

Will post some pics tomarrow to have a better overall idea of the problem.

Happy Boating
 
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steelespike

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Maybe double check your pressure with another gauge.
Chinewalking doesn't seem possible if the bow is so low. it may be bow steer or some other inflatable quirk.
 

Frank Acampora

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Jan 19, 2007
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Giving the dealer a test ride and a chance to correct the problem might be a better course rather than "popping" off and trying to return it without any dealer input.
 

Sea Rider

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Frank,

The issue with new kid in town (dealer) is that he doesn?t know what he sells. Has 0 skills on inflatables and engines. Anyway, pics speaks for themselves, If more weight is placed up front along more throttle, the more water will splash to bow sides. Pics were shot on non wind, flat calm sea cond at slow plane speed. Water performance gets worst at + speed.
Seamax 430-4.JPG

Seamax 430-5.JPG

Engine is well height seated and trimmed, air chambers are fully topped inflated with professional gauge, weight is evenly deck distributed. Seems a factory flaw issue.

Happy Boating
 
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UncleWillie

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Oct 18, 2011
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...Trim is spot on, if moved from second hole to first or third hole water performance gets worst. Second is ideal...
If the trim was "Spot On", you would be happy in how it handles.
The pictures in Post #12 look like the engine is trimmed waaaay too far Down.
When you say, "If moved from second hole to first or third hole, water performance gets worse". Describe the differences. ??
Even if hole 3 didn't make you happy, still try holes 4 and 5 just to humor us!
You are plowing in the pics, get the bow up.
Try both passengers in the rear or the front person at least in the middle instead of fully forward.

And, if you are going to sit on the tubes of a squirrelly boat, Please, put on your life jackets!
 

Sea Rider

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Sep 20, 2008
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UW,

This inflatable definitely has a hull issue. Have tried mowing weight at different positions, playing with trim setttings. This inflatable already has a chine walking behaviour with trim set at second hole best water performer. At first and third hole chine walks worst. At fourth or fifth hole inflatable will surely skyrocket to the moon...The front man is not seated fully upward, seats at a fixed immovable transversal wooden seat placed at about 1/3 boat's lenght to bow. Will continue the experimentation.

Happy Boating
 
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