One dive or two?

[Line Squirrel]

A discussion around the fire pit the other evening made me curious.

I know instructors count this as two dives, but after training, do you continue to count [as an example] from Orange Grove to Challenge and back as one dive or two?

My self imposed rule is, unless I take tanks off it's one dive for me.

[BobK]

I generally count it as one dive. Largely because, with my air consumption, I seldom make it :-)

[defunct]

what is this "log" that you speak of for dives?

[MORGAN]

what is this "log" that you speak of for dives?

Maybe it is the "deco log" in the Ear!

Mike

[WJH]

I count it as one. I made the dive with a buddy (not my usual buddy!) who surfaced for 5 minutes to count it as 2 dives -- PADI style. I counted it as one dive that day as well, just added up the time from the 2 dives logged by my computer and put them together as one dive in my written log.

WJH

[FW]

This is a really hard call, especially the example you give. Since there is little chance to get out of the water at Challange, or Pothole, I would make them one dive. Olsen is a little different, you can surface there, and talk awhile, or even get out of the water (not allowed by, PSSP of course).

Most of my "traverses" you can get out of the water, but not out of the cave, and I do take off my gear.

[SuPrBuGmAn]

For my log book...

It would depend on the SI, if its significant, probably two. By significant, I'd mean more than just surfacing to discuss an issue and take a look to see... whatever it is we see.

If I don't surface at all... one.

[Line Squirrel]

This is a really hard call, especially the example you give. Since there is little chance to get out of the water at Challenge, or Pothole, I would make them one dive. Olsen is a little different, you can surface there, and talk awhile, or even get out of the water (not allowed by, PSSP of course).


Not sure why I picked OG to Challenge [and back] as an example, probably because I had just done that dive the day before and it was fresh in my mind.

Pothole would have never occurred to me, mainly because I have always considered it an emergency egress, although I know some do surface there. I started to surface one time just to take a peek but the silt & loose "stuff" raining down from my exhaust bubbles, I decided it was better not to and dropped back down.

P1 to Olson would have been a better example since so many instructors do this with their students.

[ajimmythekid]

What ever the puter says

[Slüdge]

If your instructor calls a dive from Peacock 1 to Olson and back two dives, you have a mighty piss-poor instructor.

Edit: Let me clarify this. I'm not talking about what you do after certification. I'm talking about an instructor that would consider this as two of the four mandatory dives for a given certification level.

[Line Squirrel]

If your instructor calls a dive from Peacock 1 to Olson and back two dives, you have a mighty piss-poor instructor.

Edit: Let me clarify this. I'm not talking about what you do after certification. I'm talking about an instructor that would consider this as two of the four mandatory dives for a given certification level.

I'm pretty sure most do.

[JeffB]

I let the students count such a traverse as two dives (after at least a minimum 10 minute surface interval) but the second dive doesn't count as one of the certification dives. They end up with at least one extra dive for the class than the minimum required.

- Jeff

[amphipod06]

Single dive. Unless I get out of the water and take my drysuit off, it is a single dive....

Dive safe,

Celia

[ajimmythekid]

If your instructor calls a dive from Peacock 1 to Olson and back two dives, you have a mighty piss-poor instructor.

Edit: Let me clarify this. I'm not talking about what you do after certification. I'm talking about an instructor that would consider this as two of the four mandatory dives for a given certification level.

Mine called it one dive each time while surfacing in Olsen both times for briefing, once to set up the circuit and the 2nd dive (after complete exit) to retrieve it while back tracking. Now I still stick to what ever the puter says because I keep a down load log.

[satchmo0016]

I would count as two dives, if you surface do you not then have to recalculate 3rds?

[chimie007]

I would count as two dives, if you surface do you not then have to recalculate 3rds?

Count as one dive in my book. I was surprised that it counted as two during one of my cave class. We chatted for more than 10 min at the surface.

As far as recalculating 3rds. You don't have to recalculate 3rds if you surface. You have made it there on third so you will make it back with what you have left.

I have recalculated thirds during dives without surfacing (not even in the cavern) and it always counts as one dive in my book.

If I don't take my tanks and get out of the water then it's one dive.

[satchmo0016]

And that's where opinions differentiate. If you surface and count it as a second dive, you should recalculate thirds, as it is a second dive.

But to each his own. :)


Count as one dive in my book. I was surprised that it counted as two during one of my cave class. We chatted for more than 10 min at the surface.

As far as recalculating 3rds. You don't have to recalculate 3rds if you surface. You have made it there on third so you will make it back with what you have left.

I have recalculated thirds during dives without surfacing (not even in the cavern) and it always counts as one dive in my book.

If I don't take my tanks and get out of the water then it's one dive.

[Line Squirrel]

if you surface do you not then have to recalculate 3rds?

I don't.

Personally, if I haven't reached thirds yet, or am right at thirds, I'm going back the exact same way and downstream, I would not recalculate thirds.

Given those parameters, surfacing would not be any different than turning a dive, from a gas management perspective.

That said, there is no denying that your way would be the more conservative, but I don't see the need.

[jimdiverman]

If I am making a traverse, and not changing tanks or even getting out of the water, its one dive. If I am just sticking my head up in the sink for a quick chat, its still just one dive.

For the record, making a traverse and staying above 5 feet in a sink long enough to reset the computer sounds a little hokey. I have several 2 hour dives in my logbook from long penetrations, and I enjoy those nice long dives and expect to make many more.

Personally, I won't be surfacing just to double the number of dives I did today.

[Howard]

As far as recalculating 3rds. You don't have to recalculate 3rds if you surface. You have made it there on third so you will make it back with what you have left.

Better think again. If you made it in on thirds, and don't re-calc. You will be planning the return trip on half of your remaining gas.

Howard

[jj1987]

Better think again. If you made it in on thirds, and don't re-calc. You will be planning the return trip on half of your remaining gas.

Howard
I'm not following what you're saying here, how is this any different than if I turn my dive at 1/3 in a cave that isn't a traverse?

Let's say if you go from manatee to sue sink on 1/3, surface with 2/3, and then turn around and complete the dive back downstream, how is this different than if you hit 1/3 5ft before you ran into open water, and turned at that point without recalculating?

[metaldector]

It's one dive.

[Howard]

you start the dive with 3000# you dive 3rds and make it to your destination ending that segment with 2000# If you turnaround and come back on the other 3rd, you will end up with a 1000#.
the post was, is this 1 or two dives. If you treat it as one dive, all should be OK. But if you are looking to plan this as 2 dives, I am saying if you turnaround at 2000# recalc 3rds your new turn pressure is ~1400# you will be hitting 3rd and keeping on going toward your intended exit.

[cavediver256]

you start the dive with 3000# you dive 3rds and make it to your destination ending that segment with 2000# If you turnaround and come back on the other 3rd, you will end up with a 1000#.
the post was, is this 1 or two dives. If you treat it as one dive, all should be OK. But if you are looking to plan this as 2 dives, I am saying if you turnaround at 2000# recalc 3rds your new turn pressure is ~1400# you will be hitting 3rd and keeping on going toward your intended exit.

Ah yes,but at that point you are heading to a known exit with your second third....same as a circuit.

[aainslie]

Don't dive thirds. Dive doubles.

Always have twice the gas that you need to exit.

In a traverse where you KNOW EXACTLY where the midpoint is and how to navigate it and there is no flow, if you hit thirds at or after the halfway point you're OK. At that stage you ahve double the gas needed to exit - on the other side.

So - on the first traverse you'd better use WAY under thirds to get to the midpoint. When you get to OG, you should recalc thirds. If you hit the midpoint before hitting that third, you're OK.

Key principle - ALWAYS HAVE DOUBLE THE GAS YOU NEED TO EXIT.

I hate "thirds". It's such a bad name as it detracts from the true intent of this rule.

And you're nuts not to recalculate thirds properly just because you don't surface. Knowledge is your friend. Knowing that you have tons of gas or the return will help you prevent panic in an emergency. Let's say you start with 3000 psi, and get to OG with 2000 psi. You don't bother to recompute so you're thinking "Sheesh! That was close! But I'm juuuuust OK to go back on thirds". You head back, and you get tangled or something, and suddenly the gremlins start muttering, "this is gonna be close... this is gonna be close...". But if you'd recalculated thirds you'd know you have plenty of time to sort it out. Since it only took 500 psi to get to the halfway point on the way there, and you have 670 psi to get there with this time through (OK 600 if you insist on doing that rounding thing), you've just bought a nice time margin and know there's less need to panic.

Your high school teacher was right... Math is your friend.

(Oh and for this exercise let's forget all those little holes you stick your head up along the way... each of which once more gives you the opportunity to recalc thirds...)

[OFG-1]

If you stick your head up at pothole each way, is it then 4 dives?

[guru caver]

If you stick your head up at pothole each way, is it then 4 dives?hey, it's as many dives as you need to feel like a man...:yawinkle: