The New and Improved Celestial Navigation Poll

[chala]

Originally Posted by deckofficer

A bit easier on the deck of the 499' training vessel Golden Bear vs a small, private boat. We were encouraged to shoot quickly and many. A lot of 4, 5, lop pinwheels, with some 7 lop pinwheels. CMA was a rather competitive atmosphere. Around 20* N, near Hawaii, was my senior cruise CN course.

And what was the chart scale?

[chala]

Given a pencil trace thickness of 0.3 mm
At 1 : 500 000 scale
((0.3 * 500000)/1000)/1852 = 0.0809 nautical mile
At 1 : 150 000 scale
((0.3 * 150000)/1000)/1852 = 0.0242
At 1 : 80 000 scale
((0.3 * 80000)/1000)/1852 = 0.0129 nautical mile, now been at the centre of the trace, the lop’s should be 0.00645 nautical mile
Looking at a sheet from last year, sea calm:
1) 0.64 nm 2) 1.178 3) 0.287 4) 0.695 5) 0.195 6) 0.246
7) 0.246 8) 0.102 9) 0.187 10) 0.466 11) 0.297 12) land on the horizon.
Bugger, no pins wheel this time and surely never ever.

[deckofficer]

Boy, you guys are hard case. A spoked pinwheel doesn't mean the all intersect at one point, but rather create a hub, like a bicycle wheel. No errant lops.

[chala]

We are more prudish we call it a cocked hat by the way what was the name of that ship? “Pinwheel cosmopolitan” (to google) it is definitely a case of head twist.

[sneuman]

Originally Posted by guyver

I don't know, doesn't using a sextant in this day and age make you feel a little like; ummmm.....

Nope. Makes me feel like:

[goboatingnow]

Ok fred I get, who's the guy in the wig , I feel I know this but....

dave

[capn_billl]

Captain Cook. I would have used Bligh

[Astrid]

Odd, but Bligh, at least from portraits, appears considerably less stern than Cook.\

http://explore.moadoph.gov.au/milestones/1158

[barnakiel]

Originally Posted by guyver

I don't know, doesn't using a sextant in this day and age make you feel a little like; ummmm.....

Ask any shrink. Nothing and nobody 'makes one feel'. What one feels is entirely a reflection of what they hold inside.

If driving a Harley makes you feel macho, do not blame Harley!

;-)
b.

[barnakiel]

And for those that feel good using sextants:

Bris sextant - Wikipedia, the free encyclopedia

provided kindly by:

Various

Love,
b.

[hummingway]

Originally Posted by Astrid

Odd, but Bligh, at least from portraits, appears considerably less stern than Cook.\

First Government House Site

I think a stern countenance may be a requirement for a portrait of an explorer such as Cook. In addition my guess was it was painted after the commission of his third voyage which, I understand, were it not for vanity he would not have, and should not have, embarked on.

[chala]

Originally Posted by deckofficer

Pinwheel, when you shoot 6 or 7 stars and all your LOP's when drawn form a pinwheel with all LOP's crossing at the same point.

Originally Posted by deckofficer

Boy, you guys are hard case. A spoked pinwheel doesn't mean the all intersect at one point, but rather create a hub, like a bicycle wheel. No errant lops.

There is a serious “Concordia” coming from the bridge there. I can do a perfect pinwheel with a radius of 20nm now, if due to clouds coverage I get only one sight then I am 20nm out. If a cocked hat of 1/2nm across can be accepted as a fix by crossing bearings, I go along with.

Originally Posted by Astrid

One nautical mile is not bad Nick, up to two is acceptable. A skilled operator using a top of the line sextant from a fairly steady ship can get within .25nm, but most of us on a small boat will be lucky to get within 1nm.

If I remember Fred (yabba dabba doo) had a rock solid car, no ecu to go wrong. A 1938 sextant still in use demonstrates great reliability and low cost. Last year 2 weeks from port I had two MFD packing up at the same time (no lightning). One started rebooting every 4 minutes, the other, 1 ½ year old and still under warranty, all his control buttons became inoperative and got stuck on the disclaimer screen and at this day still is. As unreliable, they are both good for the dump, which means I will have also to replace the radar too. In that type of situation it is good to have an exit strategy.

On a lighter note why is it that we have 8 entries striving for perfect pinwheel position an only 1 for The hubby/wife does it?

[susanna reiter]

Yeah Astrid....Cook looks likes he smells something unpleasant....or..maybe he can't read a chart...LOL

[deckofficer]

Originally Posted by chala

There is a serious “Concordia” coming from the bridge there. I can do a perfect pinwheel with a radius of 20nm now, if due to clouds coverage I get only one sight then I am 20nm out. If a cocked hat of 1/2nm across can be accepted as a fix by crossing bearings, I go along with.

You got me. How about the scale being a 16" beach ball globe and your drawing your LOPs with a 1/8" wide magic marker?

[chala]

Originally Posted by deckofficer

How about the scale being a 16" beach ball globe and your drawing your LOPs with a 1/8" wide magic marker?

Originally Posted by chala

And what was the chart scale?

That was the point.
All best.