Suggestions on how to reduce my boat from "sharking" at slow speeds

rob5 · May 23, 2012

Good morning, iBoats forum. I'm a new new member and I'm very glad I've found this resource. This is my first time posting so please don't beat me up too bad if I say something ignorant...

Here's my issue - I have a small 18' sterndriven bowrider and at slow speeds it "sharks" back and forth considerably (I'm not sure if that's a real term, but that's about the best name I've heard which describes this effect). I can compensate with a fun little rhythmic steering maneuver, but this gets old very quickly (and thank heaven for power steering)... I've also tried different approaching speeds from plane to idle with no noticeable improvement.

Am I doing something grossly wrong or does this have to do with the hull design? Any suggestions on how I can prevent or reduce this would be greatly appreciated.

Thank you for your time and have a great day,
Rob

etracer68 · May 23, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

Most deep v hulls "wonder" at low ( under 10mph ) speeds, but shouldnt at mid to planing speeds.

BoatDrinksQ5 · May 23, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

Mine also does that - (new to sterndrive) and noticed if i trim up high it helps a bit.

Also if you just "let go....use the force"....don't steer - let it 'wander' you'll find it usually is a cycle and you end up pretty much going straight!

rob5 · May 23, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

BoatDrinksQ5 said:
Mine also does that - (new to sterndrive) and noticed if i trim up high it helps a bit.

Also if you just "let go....use the force"....don't steer - let it 'wander' you'll find it usually is a cycle and you end up pretty much going straight!

Excellent... Thanks BoatdrinksQ5, I'll try that.

jdlough · May 23, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

Nauticus Smart Tabs help this (and other things).

Kinda like the fletching on arrows keeps them going straight.

nlain · May 23, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

I is the nature of the beast, deep V single prop, they all wander at low speed. We the operators usually make it worse by trying to correct it. Smart Tabs will just about stop that from happening and they will do a lot of other good things for your boat.

mnypitboat · May 23, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

I second the Smart Tabs on this issue. It will also help your on plane porpoising as well. They are an inexpensive alternative to real trim tabs for smaller boats and really do a lot to help many minor issues.

QC · May 23, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

For clarity, any trim tab setup, full down will help with displacement speed wander.

Because you mention wander at planing speeds, I think you should search for info regarding your gimbal ring in the appropriate engine and drive section (Mercruiser? Vovlo? OMC?).

Oh, and welcome aboard!!

rob5 · May 24, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

Thank you all very much for your suggestions. I really appreciate your time and will look into the smart tabs.

thanks again,
Rob

Philster · May 24, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

rob5, what make of boat is that in your avatar?

I keep mental notes of brands/hulls that have issues on plane.

rscot138 · May 24, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

I've heard this called "Bow Steer" and "Wander" before also. It always seems like the more you try to correct it, the worse it gets.

rob5 · May 27, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

My boat is a 1996 Starcraft 1810 with a 4.3L Mercruiser V6. I'm purchasing the Nauticus Smart tabs and can't wait to try them out.

rob5 · May 27, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

rscot138 said:
I've heard this called "Bow Steer" and "Wander" before also. It always seems like the more you try to correct it, the worse it gets.

That's true and it's definitely not a skill I want to develop any further.

jayhanig · May 28, 2012

Re: Suggestions on how to reduce my boat from "sharking" at slow speeds

rob5 said:
My boat is a 1996 Starcraft 1810 with a 4.3L Mercruiser V6. I'm purchasing the Nauticus Smart tabs and can't wait to try them out.

I think you're going to like them... a lot.

Suggestions on how to reduce my boat from "sharking" at slow speeds

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