Stability/GZ number/advice

[Bluesbreaker]

I have a yacht that is no longer in production and desperatly require the GZnumber.Can anybody advize me of the steps to take .Thanks in anticipation.

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[qsiv]

If you can lay your hands on a full lines plan, then calculating a GZ curve (rather than number) is possible. Other than that you can do it without a lines plan by a proces known as inclining - provided you have a quiet windless day. It is relatively straightforward, requires only basic equipment and methodical approach. The smaller the boat the more diofficult it is to perform an accuarte inclining test, but with care and attention to detail it is quite possible to cover most of the range - at least until deck edge immersion, and stopping just short of the downflooding angle if you're brave. Only the foolhardy would really want to explore the AVS via such an experiment!

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[aod]

Well who built it because they must know the designer and in turn they will have calculated the GZ.

If he/she is dead the only other way I can think of is to contact the RORC and ask for details of someone near you who can perform the check properly.

Lots of this going on right now because of the new STIX measurement/requirement.

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[Bergman]

I would not guarantee that

I spoke to the designer of my boat (a well known and respected name) several years ago to try to find just this information.

He did not have a clue!

I suggested that it must be one of the basic starting points in designing a boat, to which he replied this was not an exact science but rather a precarious existance.

I gave in at that.

The RYA had a formula that gave a rough indication of the AVS, but I think to get an accurate figure needs the inclining test which will need to be carried out by a surveyor if the answer is to have any meaningful use.

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