Info Why are tables not taught in OW classes anymore?

[tursiops]

This is a very good discussion of the sextant and Apollo missions.

Nerdfighteria Wiki - The Old Sailors' Tool That Saved Apollo 13

The Old Sailors' Tool That Saved Apollo 13

nerdfighteria.info

They not only made it, but they in Apollo 13 came within 2 miles of their recovery ship

Now, that comment about always having a Plan B applies to divers too, hence tables or a backup computer.

SeaRat

Nice.
I only used a sextant once, when on a long oceanographic cruise and one of my shipmates was a Power Squadron instructor. He showed me how to use it, and I did the sightings, used the book, looked at the clock, and announced our position. This was pre-GPS, but we did have Loran-C. I was off by about 2 miles. My friends said, "Don't ever do this again, you'll never get as close as that again!"

 

[Pressurehead]

I think the tables were tattooed on my brain forever after using them for so many years, like my Navy official number, I would forget my kids names before I forget those tables and number.
Now I dive with 2 computers and don't over think it.
Such fun.

 

[John C. Ratliff]

We need the log of your dives from earlier that day to complete the problem.

I'll let the altitude stuff go, and you can calculate the dive using #145, 146 and 147. . For the calculations, use 1/2 hour surface interval between each dive.

SeaRat

 

[Bigbella]

Against my better judgement, I wandered into a Starbuck's on the way back from Monterey on Friday; and aside from them blasting their typically shrill "women who cut themselves" collection over the speakers, also noticed that three comely CSUMB students, were pouring over textbooks and futzing with NAUI tables.

All is not lost . . .

 

[lowwall]

I'll let the altitude stuff go, and you can calculate the dive using #145, 146 and 147. . For the calculations, use 1/2 hour surface interval between each dive.

SeaRat

Recap:
145: 90' 25 minutes
30 minute SI
146: 40' 35 minutes
30 minute SI
147: 40' 30 minutes

What time did you surface on dive 147? Are we supposed to assume 5:30pm?

BTW, you should check the "Total" column on dive 146 (and therefore 147)

It's kind of cool to be discussing 50 year old dives. Maybe I should reconsider about not logging my dives.

 

[Superlyte27]

The abacus is still used, especially in certain Asian shops.

Show me where it’s taught in any high school or college as a normal class.

 

[agilis]

Show me where it’s taught in any high school or college as a normal class.

We no longer teach Civics, either. Use of an abacus sharpens and informs mathematical perception and insight. In a learning context understanding is better than pushing buttons to get an answer.

 

[Centrals]

Mental abacus - Wikipedia

en.wikipedia.org

No need for calculator, paper, pen and a actual abacus.

 

[Vertologist]

Thanks for this discussion and the explanation, @tursiops and others. I'm a beginning diver, just OW this past summer, and thought it strange that the PADI course never had us look at tables. Now I have a better sense of why. I rely on my computer, but haven't sprung for a backup yet. Glad to hear the experiences of more capable divers!

 

[tursiops]

Thanks for this discussion and the explanation, @tursiops and others. I'm a beginning diver, just OW this past summer, and thought it strange that the PADI course never had us look at tables. Now I have a better sense of why. I rely on my computer, but haven't sprung for a backup yet. Glad to hear the experiences of more capable divers!

Welcome to underwater!
If you are curious about the tables, ask your instructor to explain them to you. They are kinda cool, actually...just not usually up to the job anymore.