Add zero and divide by 6?

Robby

Robby

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Hi,
I hope someone can help with a rather odd question.
When my dad took his Yachtmasters quite a few (many) years ago, they used the above technique (multiply by 10 and divide by 6) as a rough conversion of some units to some other units. However, at 82 he can't remember what he was converting at the time.
I suggested it could be Km to miles but he doesn't think it was.

Can anyone remember or suggest what the conversion involved?

Thanks,
Robby.
 
Years ago, did Yachtmasters really bother about Km? Or metres for that matter.
I'll go out on a limb and suggest that it might be a slightly mis-remembered formula for converting steering error to distance off course, or cross track error in modern speak.
One degree error gives approx. one sixth of a mile for ten miles travelled.
 
Last edited:
Robby said:
Hi,
I hope someone can help with a rather odd question.
When my dad took his Yachtmasters quite a few (many) years ago, they used the above technique (multiply by 10 and divide by 6) as a rough conversion of some units to some other units. However, at 82 he can't remember what he was converting at the time.
I suggested it could be Km to miles but he doesn't think it was.

Can anyone remember or suggest what the conversion involved?

Thanks,
Robby.
Click to expand...


Think it might have been wind force.

ADD 10 ( to knots) divide by six.
 
Miles to km is X8 dev 5 ,so, apart from relevance (wind speed?) sounds like something else.
A
Ed: Might be a quick fix for the same.
 
Last edited:
miles to km. add 0 and divide by 6 is the same as saying multiply by 1.6. so since a km is 5/8 of a mile ...................

what that has to do with nav I don't know.

it's not far off fathoms to metres either
 
Could your father have it slightly wrong? Could it be subtract the nought and divide by six? Gives you seconds" to decimal minutes'.
Applicable if you had an older style vernier sextant and decimal tables.
 
Distance travelled in 6 minutes perhaps

Robby said:
Hi,
I hope someone can help with a rather odd question.
When my dad took his Yachtmasters quite a few (many) years ago, they used the above technique (multiply by 10 and divide by 6) as a rough conversion of some units to some other units. However, at 82 he can't remember what he was converting at the time.
I suggested it could be Km to miles but he doesn't think it was.

Can anyone remember or suggest what the conversion involved?

Thanks,
Robby.
Click to expand...

Divide speed (in knots) by 10 = distance travelled in 6 mins (nautical miles).
 
Thanks for the replies

Many thanks for your prompt replies, I'll note them all and see if any of them jogs his memory.

Robby.
 
Two other (similar sounding) usedful rules of thumb.
a) To convert knots to Beaufort, add 5 to the windspeed in knots, then divide by 5
b) Too convert mph to Beaufort, add 6 and divide by 6
 
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