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Old 05 September 2001, 02:12   #1
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Porpoising

Is porpoising dangerous or just annoying ?

Is it the result of weight distribution or can it be the result of
overpowering as well ?

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Dimitris
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Old 05 September 2001, 02:15   #2
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Okay, just to prove that I'm always the one to ask an apparently daft question, what exactly is porpoising?

Keith Hart
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Old 05 September 2001, 02:23   #3
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It is a continous up and down movement of the bow even when the water is dead calm

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Old 05 September 2001, 02:27   #4
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Thanks, I just knew there would be a simple answer. If it happens to me now at least I'll know what to call it!

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Old 05 September 2001, 02:28   #5
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Oh, sorry, I forgot to ask....what does 'dead calm' mean?

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Old 05 September 2001, 02:52   #6
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Go to Hotribs.com and there is an article within the section this link takes you to about the subject (features section)

http://www.hotribs.com/members/default.cfm

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Old 05 September 2001, 03:05   #7
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To save you arriving at HotRIBs then casting round wondering what on earth to click on next, here are some direct links:

Porpoising article
Trimming devices part 1
Trimming devices part 2

If your RIB is porpoising it generally means that it is not set up correctly, and is not running as efficiently as it could. It may simply be a matter of having the engine trimmed too far out, or it may be something more fundamental in the setup of the boat.

At lowish speeds it's not a big deal (although annoying) at high speeds it can become dangerous as the oscillations grow in size and more control is lost.

John
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Old 05 September 2001, 05:38   #8
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Dimitris,

I don't think that over power could have this result.

Michael
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Old 05 September 2001, 14:05   #9
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Thanks for the responses.

The links to hotrib provided me with an understanding of the phenomenon and it's posible solutions.

As of next week, I am starting the project of re-distributing weights on my boat.

All the problems started when I added a second 90 liter tank.

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Old 06 September 2001, 06:19   #10
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Dimitris,

Where did you installed the 90 lit. tank ?

Michael
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