"Stupid human trick"--estimate bearings without yr compass - SailNet Community
 9Likes
  • 3 Post By nolatom
  • 2 Post By Seaduction
  • 3 Post By deniseO30
  • 1 Post By smurphny
 
LinkBack Thread Tools
post #1 of 9 Old 08-07-2013 Thread Starter
Senior Member
 
Join Date: Jun 2005
Location: New Orleans
Posts: 1,999
Thanks: 8
Thanked 37 Times in 34 Posts
Rep Power: 11
 
"Stupid human trick"--estimate bearings without yr compass

So, here's a "stupid Human trick"--estimating degrees of angle w/o instruments

Did you ever want to be able to easily determine approximately how many compass degrees something is from something else?

there's a simple way, no equipment needed (even though yes, you do have a compass I hope).

On average, a fist (with thumb on top, not wrapped around the fingers), on an arm fully extended in front of your eyes, describes an arc of ten degrees, from bottom of pinky finger to top of thumb.

So--is boat A two fists off your headstay? that's 20 degrees. Try doing this with nine fists in succession and you'll see you've made a right angle (90 degrees), whether you are moving horizontally for a terrestrial object, or vertically for a celestial one.

And you can be a latitude-navigator without a sextant. Find the North Star (Big Dipper outer two stars of the spoon point you towards Polaris). Either see (twilight) or estimate your horizontal horizon, and go fist-over fists up to Polaris. Four fists? You're at 40 degrees latitude (Massachusetts!). 3 Fists? New Orleans (I know this one, 30 degrees north of the equator). Latitude navigators discovered the world centuries before they figured out how to find longitude.

How long til sunset (Moonset)? Easy. How many fists from sun down to horizon, or vice-versa? 4 and a half fists? that's 45 degrees. The sun (and all sky objects) "move" at 15 degrees an hour (since Earth rotates 360 of them in 24 hours, si?). So you have 3 hours to finish that dive, or that round of golf. Each fist is worth 10 degrees, so that's 40 minutes of movement. So, if you want cut it closer, each finger/knuckle is worth about 2 degrees, or 8 minutes.

And, a fist is almost 11-1/4 degrees, which is a "Point" forus sailors and historians ("Land ho, 3 points off the port bow!!" a point being 360 degrees divided by 32, if you've ever "boxed" the compass). Now you know what they're talking about in "Moby Dick" and such.

So the human trick ain't so stupid, eh? (hey, trust me, I'm an English Major)
eherlihy, JSL3 and groggy like this.

Last edited by nolatom; 08-07-2013 at 11:35 AM.
nolatom is offline  
Quote Quick Reply Share with Facebook
The Following 3 Users Say Thank You to nolatom For This Useful Post:
jlaskowsky73 (08-08-2013), mstern (08-07-2013), wingNwing (08-07-2013)
Sponsored Links
Advertisement
 
post #2 of 9 Old 08-07-2013
Senior Member
 
mstern's Avatar
 
Join Date: May 2002
Posts: 767
Thanks: 19
Thanked 8 Times in 7 Posts
Rep Power: 14
 
Re: "Stupid human trick"--estimate bearings without yr compass

Thanks! Can't wait to look smart.
mstern is offline  
Quote Quick Reply Share with Facebook
post #3 of 9 Old 08-07-2013
Senior Member
 
Join Date: Oct 2011
Posts: 1,420
Thanks: 13
Thanked 24 Times in 24 Posts
Rep Power: 4
 
Re: "Stupid human trick"--estimate bearings without yr compass

I used to lie on my back and look straight between my right and left big-toes and see Johnny Carson.
kellysails and RainDog like this.
Seaduction is offline  
Quote Quick Reply Share with Facebook
post #4 of 9 Old 08-07-2013
me at 67!
 
deniseO30's Avatar
 
Join Date: Nov 2006
Location: Bristol pa
Posts: 6,925
Thanks: 55
Thanked 125 Times in 114 Posts
Rep Power: 10
   
Re: "Stupid human trick"--estimate bearings without yr compass

Best direction finder; Tell her there's a fashion outlet mall at the proposed destination!
carl762, MarkofSeaLife and jimgo like this.

Denise, Bristol PA, Oday 30. On Tidal Delaware River, Anchor Yacht Club.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

My last project!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


My boat is sold!
deniseO30 is offline  
Quote Quick Reply Share with Facebook
post #5 of 9 Old 08-07-2013
Senior Member
 
mstern's Avatar
 
Join Date: May 2002
Posts: 767
Thanks: 19
Thanked 8 Times in 7 Posts
Rep Power: 14
 
Re: "Stupid human trick"--estimate bearings without yr compass

Quote:
Originally Posted by deniseO30 View Post
Best direction finder; Tell her there's a fashion outlet mall at the proposed destination!
My wife is a thoroughly brilliant businesswoman. I mean really talented. But she has a terrible sense of direction and absolutely cannot read a map. However, she has what I have come to call "Mall Radar". She can find (perhaps by sense of smell or some weird disturbance in the magnetic fields of the Earth) just about any retail establishment on the face of the planet. And she can unerringly find a parking space at any mall, even during the holidays. Its uncanny. I intend to try out Denise's suggestion.
mstern is offline  
Quote Quick Reply Share with Facebook
post #6 of 9 Old 08-07-2013
Senior Member
 
MarkofSeaLife's Avatar
 
Join Date: Nov 2010
Posts: 2,962
Thanks: 42
Thanked 122 Times in 103 Posts
Rep Power: 5
 
Dock
Re: "Stupid human trick"--estimate bearings without yr compass

So if someone comes too close and you shake your fist at them 10 times they will turn around and piss off?


Thanks, thats good to know.


Mark

Sea Life
Notes on a Circumnavigation:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
MarkofSeaLife is offline  
Quote Quick Reply Share with Facebook
post #7 of 9 Old 08-07-2013
Senior Member
 
Join Date: Oct 2011
Posts: 1,420
Thanks: 13
Thanked 24 Times in 24 Posts
Rep Power: 4
 
Re: "Stupid human trick"--estimate bearings without yr compass

Nolatom, you're absolutely right to know how to figure stuff like that out using commonplace items. Its a very useful skill. That's the kind of stuff I used to mention at social gatherings and everybody would roll their eyes and kind of back away. People like us know that Polaris is more than a wave-runner or snowmobile. Nerds of the world unite! Maybe we could nominate a president!
Seaduction is offline  
Quote Quick Reply Share with Facebook
post #8 of 9 Old 08-07-2013
Senior Member
 
ebs001's Avatar
 
Join Date: May 2006
Location: Ottawa, Canada
Posts: 2,205
Thanks: 6
Thanked 21 Times in 19 Posts
Rep Power: 10
 
Re: "Stupid human trick"--estimate bearings without yr compass

Quote:
Originally Posted by nolatom View Post
So, here's a "stupid Human trick"--estimating degrees of angle w/o instruments

Did you ever want to be able to easily determine approximately how many compass degrees something is from something else?

there's a simple way, no equipment needed (even though yes, you do have a compass I hope).

On average, a fist (with thumb on top, not wrapped around the fingers), on an arm fully extended in front of your eyes, describes an arc of ten degrees, from bottom of pinky finger to top of thumb.

So--is boat A two fists off your headstay? that's 20 degrees. Try doing this with nine fists in succession and you'll see you've made a right angle (90 degrees), whether you are moving horizontally for a terrestrial object, or vertically for a celestial one.

And you can be a latitude-navigator without a sextant. Find the North Star (Big Dipper outer two stars of the spoon point you towards Polaris). Either see (twilight) or estimate your horizontal horizon, and go fist-over fists up to Polaris. Four fists? You're at 40 degrees latitude (Massachusetts!). 3 Fists? New Orleans (I know this one, 30 degrees north of the equator). Latitude navigators discovered the world centuries before they figured out how to find longitude.

How long til sunset (Moonset)? Easy. How many fists from sun down to horizon, or vice-versa? 4 and a half fists? that's 45 degrees. The sun (and all sky objects) "move" at 15 degrees an hour (since Earth rotates 360 of them in 24 hours, si?). So you have 3 hours to finish that dive, or that round of golf. Each fist is worth 10 degrees, so that's 40 minutes of movement. So, if you want cut it closer, each finger/knuckle is worth about 2 degrees, or 8 minutes.

And, a fist is almost 11-1/4 degrees, which is a "Point" forus sailors and historians ("Land ho, 3 points off the port bow!!" a point being 360 degrees divided by 32, if you've ever "boxed" the compass). Now you know what they're talking about in "Moby Dick" and such.

So the human trick ain't so stupid, eh? (hey, trust me, I'm an English Major)
Thanks, good human trick. Now we can say "So the human trick ain't so stupid, eh? (I read on the internet)
ebs001 is offline  
Quote Quick Reply Share with Facebook
post #9 of 9 Old 08-07-2013
Over Hill Sailing Club
 
smurphny's Avatar
 
Join Date: Feb 2009
Location: Adirondacks NY
Posts: 3,447
Thanks: 86
Thanked 99 Times in 96 Posts
Rep Power: 7
 
Re: "Stupid human trick"--estimate bearings without yr compass

There's also the Buys Ballots Law trick, using the spread between thumb and pinky when your hand is stretched open as the angle between a storm's center and wind direction. Both handy tricks. Then, of course, there's another useful nautical hand signal: arm straight up vertically or sometimes rapidly hooked under the other arm and then thrust upwards, enumerating 1 with the center finger. It is often flashed to power boaters after they wake you.
rugosa likes this.

Alberg 35: With a philosophical flourish Cato throws himself upon his sword; I quietly take to the ship.

Last edited by smurphny; 08-07-2013 at 07:01 PM.
smurphny is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
"Seacock" vs. "ballcock" or "ball valve?" SEMIJim Gear & Maintenance 18 09-02-2013 05:31 PM
Fluxgate compass and the st4000 Wheel "HELP" ltgoshen Electronics 12 05-18-2013 02:44 PM
C270 Main Sail "stack Pack", Quick Cover", "lazy Bag" Install randy22556 Catalina 1 02-28-2007 11:53 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome