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Old 03-27-2007, 02:13 AM
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Default Big waves headed at 20 degrees angle: why?

Hi All,

I was just wondering why shall big waves be headed at around 20 degrees angle and not strait ahead?

I always kept at zero and felt it was the safest

I would hate to feel something big moving the boat side to side.

thanks for clarifications
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Old 03-27-2007, 07:11 AM
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Default Re: Big waves headed at 20 degrees angle: why?

XV2,
Where are you getting the 20 degrees from? For what boat, in what type of sea, at what speed?
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Old 03-27-2007, 07:46 AM
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Default Re: Big waves headed at 20 degrees angle: why?

Well several time I have been reading here about give a slight angle (I think 20 degrees were mentioned) to very big waves. Now for the speed and type of boat, I did not see any description, but I guess speed shall be slow. Of course this is in case of dangerous waves/wakes.
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Old 03-27-2007, 07:59 AM
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Default RE: Big waves headed at 20 degrees angle: why?

I have a small boat and I've found there is no set angle that works every time. A lot depends on the speed you are wanting to travel. My objective is to keep my boat in contact with the water so I hit them at as shallow angle as possible and let the waves roll under me if I'm going pretty fast. I often zig and zag to a location instead of heading straight to the spot just for an easier ride.For sheer comfort at trolling speeds, a slight angle helps keep the boat from slamming or droppiing off the back of the wave if your direction allows for an angle.
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Old 03-27-2007, 08:18 AM
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Default Re: Big waves headed at 20 degrees angle: why?

There are a number of variable factors to consider when deciding how to 'take' the waves. Hull, length and type, speed, wind speed and direction, wave height, frequency and direction, relative to course heading must all be taken into account. There is no formula, per se, that dictates how to accomodate these existing conditions other than your own judgement at the time. Good sense and experience will show you how to acheive the best ride under existing conditions.
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Old 03-27-2007, 09:03 AM
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Default Re: Big waves headed at 20 degrees angle: why?

i think it comes from sail boats where you cant head into the wind
i find, although i may be wrong..a near on full the best..it doesnt throw my bow off
also when runnig off..i lean into the wave with the steering to give directional stability
dont know what is right or wrong....only what i like
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Old 03-27-2007, 09:09 AM
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Default Re: Big waves headed at 20 degrees angle: why?

I am only speaking of large breaking waves that have the ability to stuff your bow. I always take those waves at a 1:00-2:00 position simply not to have the wave break over my bow. ON a center console water breaking over the bow can mean disaster. I also find its much smoother and safer when doing so. Keep in mind- This is at trolling speeds no more then 10 knts in real bad seas. I wont go faster in really bad weather. For choppy seas I just cut right thru headon at 50knots skipping accross the top and bulging the discs in my back.

As NJmello mentions, every scenario is different and it simply comes down to good judgement and experience.
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Old 03-27-2007, 09:23 AM
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Default RE: Big waves headed at 20 degrees angle: why?

Quote:
XV2PS - 3/27/2007 1:13 AM

Hi All,

I was just wondering why shall big waves be headed at around 20 degrees angle and not strait ahead?
Assuming you do not have the hull length to ride across the tops of the waves...

Heading straight into the wave on a plane the boat experiences the full angle (steepness) of the wave and is lifted that full angle. After cresting the peak the hull then drops to ride down the full angle of the wave.

By taking the waves at an angle you decrease the effective angle (less steep) by increasing the distance travelled up the face of the wave. the same thing occurs as you head down the back of the wave. This effectively increases the apparent (as travelled by the boat) wavelength becasue the boat travels the distance from the peak to the trough to next peak over a longer period of time and distance.
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Old 03-27-2007, 09:27 AM
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Default Re: Big waves headed at 20 degrees angle: why?

Quote:
pjlexydaddy - 3/27/2007 8:09 AM

I am only speaking of large breaking waves that have the ability to stuff your bow. I always take those waves at a 1:00-2:00 position simply not to have the wave break over my bow. ON a center console water breaking over the bow can mean disaster.
It is far worse to have a breaking wave come over your gunwales in a CC.
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Old 03-27-2007, 11:20 AM
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Default Re: Big waves headed at 20 degrees angle: why?

It's to avoid pitch-pole phenomenon. If you come down the face of a big one at 90 degrees there is a probability that you may go end over end from burying the bow, and orthe next wave lifting the stern over. Approaching from an angle allows you to try and pick a line and surf down the face of the wave. You may refer to CG Aux Boating Skills and Semanship documents.
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Old 03-27-2007, 11:43 AM
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Default Re: Big waves headed at 20 degrees angle: why?

or ya could get a boat with a decent bow on it
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Old 03-27-2007, 12:08 PM
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Default Re: Big waves headed at 20 degrees angle: why?

You're kidding, right? In heavy weather this is not trivial. A good squall can take it from dead calm to close 15 footers in a brief time. Forget making headway, just being under power and attempting to keep the bow into the seas is a task even for a very substantial vessel. I believe it is unfortunate and troubling that this basic safety fact of seamanship elicits an inquiry.
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Old 03-27-2007, 12:54 PM
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Default Re: Big waves headed at 20 degrees angle: why?

Asenaotie hit the nail on the head. It increases the apparent wavelength.

Jack
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Old 03-27-2007, 12:55 PM
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Default RE: Big waves headed at 20 degrees angle: why?

my guess: in a "big wave" relative to your boat, you will be descending into the trough on a regular basis...at 0* the trough is "narrow" and the steepness in your decline may cause the bow to bury in the sea...by taking it at an angle, you "widen" the trough and decrease your angle of descent (and ultimate incline)...thereby reducing the potential for driving your bow underwater.

what constitutes a "big wave" is probably much bigger than what we generally consider big and can handle dead on.


ETA...guess I should have read the other responses first...Oh well...good to know I can still guess right occassionally.
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Old 03-27-2007, 12:57 PM
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Default Re: Big waves headed at 20 degrees angle: why?

Tireless.
I agree, but taking water in over the bow will most likely cause the boat to list(depending on how much water and your deck drainage) thus making it unstable and easier for water to enter over the gunwhales on the next set. In most cases taking a wave at 1:00 will not cause water to enter over the gunwhales. Every wave is diferent and needs to be handled differently.
I have been using this technique for over 20 years and no boats lost.
Dead on into steep waves will in most cases break into your boat. Smaller boats like mine. 24ft center console.
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Old 03-27-2007, 01:02 PM
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Default Re: Big waves headed at 20 degrees angle: why?

Another vote for Asenaotie's explanation. My experience has been that taking waves at an angle as opposed to straight on is much more comfortatble. Bow does not ride up as high nor does it come crashing down as much.
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Old 03-27-2007, 02:09 PM
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Default Re: Big waves headed at 20 degrees angle: why?

Quote:
jethro1 - 3/27/2007 12:02 PM Another vote for Asenaotie's explanation. My experience has been that taking waves at an angle as opposed to straight on is much more comfortatble. Bow does not ride up as high nor does it come crashing down as much.




makes good sence to me

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Old 03-27-2007, 02:27 PM
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Default Re: Big waves headed at 20 degrees angle: why?

All ya need is 24 degrees of deadrise, or a Panga... Doesn't anyone read anything besides Suzuki threads here?
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Old 03-27-2007, 02:38 PM
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Default Re: Big waves headed at 20 degrees angle: why?

well, simplified, you are going to go up a slope from the trough of the wave to the peak of the wave. If you do it head on, its a short steep slope. At an angle, its a longer trip.

Its the difference between driving straight up the hill, or taking a path with switchbacks. Same thing as what that wavelength dude said. he's right.
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Old 03-27-2007, 02:41 PM
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Default Re: Big waves headed at 20 degrees angle: why?

Quote:
Tireless - 3/27/2007 3:27 AM
Quote:
pjlexydaddy - 3/27/2007 8:09 AM I am only speaking of large breaking waves that have the ability to stuff your bow. I always take those waves at a 1:00-2:00 position simply not to have the wave break over my bow. ON a center console water breaking over the bow can mean disaster.
It is far worse to have a breaking wave come over your gunwales in a CC.
Yuup, I fully agree. I'd much rather take the hit straight-away and have the force or momentum of that water running directly aft towards my transom door (i.e., in the two channels lateral to the console) than have it hit (full force) on the inside wall of a gunwale. If the wave were large enough, I think the latter scenario would have a better shot at dumpingme in a deep-v.
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