Deprecated: Function set_magic_quotes_runtime() is deprecated in /var/www/vhosts/tartan37.com/httpdocs/t37forum/common.php on line 88 Tartan37.com • View topic - Things all sailors should know - 6 min. rule (3 min rule)

Tartan37.com

Tartan 37 Owner's Forum - Ride the wind, but look good doing it!
The time is 28 Nov 2020 17:59

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 2 Posts ] 
Author Message
 Post subject: Things all sailors should know - 6 min. rule (3 min rule)
PostPosted: 17 Nov 2007 12:44 
Offline
Skipper

Joined: 20 Oct 2006 16:10
Posts: 682
Location: Out of Waukegan, IL
This is the simplest of them all and very handy for not looking to the GPS every 5 minutes.

6 minutes is 1/10th of and hour. So in 6 minutes your travel 1/10th of your speed in distance. Not handy at all unless you convert to yds. (again, we're using 2000yds - 1 NM.)

Doing 5 kts, so it 6 minutes we'll travel 1000 yds. (5 x 2000 = 10000 / 10 = 1000.)
So to skip the math, here's the rule.

Six Minute Rule: Speed in kts * 2, then add two zeros (shift the decimal two places) and you have the yards you'll travel.
8kts will be 1600 yds in 6 min.
3 kts will be 600 yds.
4.6 kts will be 460 yds.

Even easier is if you need to keep it in miles you're just moving the decimal.
6 kts will be .6NM in 6 min

Three minute rule is the same but don't double the number. Just shift the decimal 2 places.
5kts = 500yds in 3 min.
4.5kts = 450 yds in 3 min.

Example: You're 3.2 miles from your harbor, you're doing 5 kts. Your wife wants to know "are we there yet". What's your reply?

3.2 miles at .5 NM each 6 minutes. 3.2/.5 is about 6 and a little bit (remember we're doing quick brain calculations here) 6*6 = 36 min.... say about 38 min.

or

3.2 miles = 6400 yds. 5kts means 1000 yds in 6 min, 500 yds in 3 min. So 6 six mins, and a little less than 1 three min. So just under 39 min.

_________________
SMMO/First Mate aboard High Flight #299
1981 - Full Keel - Furling Main (A boat for the lazy crew...)


 
 Profile Email  
 
 Post subject: Re: Things all sailors should know - 6 min. rule (3 min rule
PostPosted: 21 Nov 2007 18:23 
Offline
Midshipman

Joined: 14 Dec 2006 22:13
Posts: 59
I think I will just refer to the GPS. Very Happy

_________________
Mark
T37 #315, Celtic Lady
Muskegon, MI


 
 Profile Email  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 Posts ] 

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Powered by phpBB © 2002, 2006 phpBB Group