Bottom Timer with Minutes & Seconds

[Uncle Pug]

MikeFerrara once bubbled...
I go by decompression run time.
Both you and Phil are using RT... that must mean that you have to keep track of RT... do you have the RT for each stop written down on a slate or something?

We just remember the stops with more than 1 minute.

For example last week we did 160' for 20 minutes:

Our first one minute stop was at 100' and everything else was one minute (except the gas switch at 70' is three minutes) until we get to the first multi-minute deco stop which happened to be at 40' for 2 minutes, 30' for 3 minutes, 20' for 6 minutes, 10' for 4 minutes (we switch the 10' and 20' stops.)

Thus we call a 160/20 using EAN50 for deco a 2,3,6,4 dive... and that is all we have to remember. First stop and all but the gas switch (always 3~5) are one minute... then we do 2,3,6,4

We do have 2,3,6,4 written down in our wetnotes but this is so simple to remember even I can do it.

[MechDiver]

Uncle Pug once bubbled...

Both you and Phil are using RT... that must mean that you have to keep track of RT... do you have the RT for each stop written down on a slate or something?



I do, yes. The slate would have three columns, the first being depth, the second RT and the third % of deco gas used. Something like

160 20
120 23 35 (gas switch)
70 28 50

The times are when you arrive in the case of gas switch, or when you leave in case of deco stop. So at minute 28 you would leave 70 ft and ascend to 60, spend one minute, then leave at 30. Hard to show without a full profile, but easy to do. We do gas switches on the fly if not at a deco stop, or you could program in a minute if wanted.

Phil

[MikeFerrara]

Uncle Pug once bubbled...

Both you and Phil are using RT... that must mean that you have to keep track of RT... do you have the RT for each stop written down on a slate or something?

We just remember the stops with more than 1 minute.




Yes and no. If My first stop is at (just to pick a number) 100 ft and the first say 3 stops are 1 minute I don't need all that written down. I do know though that there is three minutes in those stops combined. I get to the first stop and time 1 minute from the next minute click and leave. After that I am leaving stops on the minute. That's what I really meant by run time.

We also run into situations like having a 7 minute swim at 45 feet as part of the ascent (cave) with a schedule that calls for say 3 min at 50 and 5 min at 40. I might do the swim and count it towards the 50 ft stop and part of the 40 ft stop. When I get to where I can continue my ascent I won't go above 40 until the 8 min has passed. Also we might have our O2 waiting at the start of the main line at 45 ft and the flow can be up or down changing the exact time of the swim. So I have the swim and the bottle pick up and a reel pick up to do in that slot. Once I start the clock on deco I am leaving each stop on time and I can check myselfe easily.

I might if I feel the need write down the time when I leave a certain stop. This gives an intermediate number to work against to minimize the math. We're diving similar depths but have longer bottom times so stops get longer deeper giving more to remember

Using your example of 2, 3, 6, 4 I might have that 7 minute swim at an inbetween depth to do during the three and the six but I won't leave the six untill 9 minutes has elapsed from when I left the 2.

I'm allways interested in ways to simplify the process though so please offer any suggestions you might have.

[WreckWriter]

I carry both deco time and RT. For your example 160' 20 m dive with 50% for deco I would have this on my wrist slate:

Stop at 90ft 0:40 (22)
Stop at 80ft 1:00 (23)
Stop at 70ft 5:00 (28)
Stop at 60ft 1:00 (29)
Stop at 50ft 1:00 (30)
Stop at 40ft 1:00 (31)
Stop at 30ft 1:00 (32)
Stop at 20ft 9:00 (41)

Of course I would have various +/- depth and time numbers too were I actually doing the dive.

WW

[MechDiver]

WreckWriter once bubbled...
I carry both deco time and RT. For your example 160' 20 m dive with 50% for deco I would have this on my wrist slate:

WW

As I'm still learning here, why do you feel it necessary to also have stop times if you have RT?

Do you also have missed depth profiles on your slate. Say for 170' in the example we're using, or are you figuring something as you go if necessary?

Phil

[Uncle Pug]

MikeFerrara once bubbled...
We're diving similar depths but have longer bottom times so stops get longer deeper giving more to remember
it starts to get not fun anymore if we stay to long... but you are right... the more stops and the longer they are the more there is to remember. But I think for the direct ascents we are doing it is much easier to just remember the numbers greater than one.

[MikeFerrara]

Uncle Pug once bubbled...

it starts to get not fun anymore if we stay to long... but you are right... the more stops and the longer they are the more there is to remember. But I think for the direct ascents we are doing it is much easier to just remember the numbers greater than one.

I still have fun but I add depth, time or complexity a little at a time because it changes things more than some would imagine.

[Uncle Pug]

MikeFerrara once bubbled...
I still have fun
I am referring to the temp difference between your water and our water. My longest dive here was 62 minutes and that just gets to be not fun! I'm a weenie. :D

[Uncle Pug]

MechDiver once bubbled...
We do gas switches on the fly if not at a deco stop
We do the gas switch at PO2 1.6 and spend enough time there for it to have an effect.... it is the gas switch deco stop.

[MechDiver]

Uncle Pug once bubbled...

I am referring to the temp difference between your water and our water. My longest dive here was 62 minutes and that just gets to be not fun! I'm a weenie. :D

We had a 82 min RT in Hood Canal last November. Even the Weezle was shivering for awhile. Ain't no weenie about it :eek:

Phil

[MechDiver]

Uncle Pug once bubbled...

We do the gas switch at PO2 1.6 and spend enough time there for it to have an effect.... it is the gas switch deco stop.

Do the same for the 50% @ 70 or 80% at 30 (I know, I know, but IANTD likes 80%). I was typing and thinking at the same time I guess.

If we're using 35% and 80%, we'll just switch over to 35% at 120 without doing a stop, then stop at 100. At 70 we'll do the same as you. I oversimplified the RT chart to get the point across.

Phil

[MikeFerrara]

I keep Great Lakes dives down to around 60-70 min total. We do that because of the temp and the OW hazards. Summer isn't bad though. Whitefish can be in the mid 60's up shallow and southern Lake Michigan can be mid 70's. those temps make for comfortable deco. The longer dives I was refering to are in a 55+ deg f cave. The guys doing the real long stuff here (the OCDA) are using electric underware and battery cans rigged like a stage bottle for their shallow stops. Their dives take all day. Our longest is I think 134 minutes (way short by comparisson) and I stayed plenty warm. My wife was starting to chill though so that's about our limit with our current equipment. On the good side the cavern zone is an interesting place to hang out so I don't get board. There is a flooded mine that we dive and it is COLD but it's also shallow so when you get cold you just end the dive.

[The Pirate]

As I'm still learning here, why do you feel it necessary to also have stop times if you have RT?

Its necessary to know the stop times because you might have a delay for some reason or another. If you only have run time and you do get delayed, when you're ready to resume your deco schedule you're going to have to back the stop times out of your run times to continue your schedule, then re-figure the run times. If you have the stop times, you can just go on from there.

The Pirate :pirate:

[Divesherpa]

Uncle Pug once bubbled...

I am referring to the temp difference between your water and our water. My longest dive here was 62 minutes and that just gets to be not fun! I'm a weenie. :D

What's the purpose of a 20minute dive to 160'? Are you just going down to do it?

Heading back to the PNW for some more wreck diving in February for a few days. We'll be freezing after the first couple of hours too. I guess it depends on the purpose of the dive, eh?

[Uncle Pug]

Divesherpa once bubbled...
What's the purpose of a 20minute dive to 160'? Are you just going down to do it?
The purpose of this dive was to find a *wall* that turned out to be a small clay bank that ran from 100' to 120'.


Heading back to the PNW for some more wreck diving in February for a few days.
What wreck?

[Divesherpa]

Uncle Pug once bubbled...




What wreck?

Don't know the name of the wrecks yet. There were quite a few discoveries over the last few months. We are basing out of Craig on Prince of Wales Island. The wrecks aren't in that great of shape, but they are plentiful. I'll send some pics if we find anything interesting. Mostly, it's just fishing boat remains or cargo barges, but I have seen some good stuff.

Are there any wrecks in your neck of the woods? It seems like there would be quite a few off the Washington coast. I know there are quite a few just north of you in southern B.C. and throughout Alaska.
Cheers

[Uncle Pug]

Divesherpa once bubbled...
We are basing out of Craig on Prince of Wales Island. The wrecks aren't in that great of shape, but they are plentiful. I'll send some pics if we find anything interesting.
I keep forgetting Alaska is PNW to you :D I thought maybe you were coming here to Western Washington!

Sounds interesting... and pictures of above and below water would be apreciated.

Shane and I have been on several of the BC *wrecks* ... intentionally sunk Canadian warships... but since neither of us have had any penetration training we just stayed outside (for the most part) ... and that gets old fast.

Once we get some training then perhaps we will make the effort to go find and dive some wrecks.

[Divesherpa]

Come on down here, Pug, and do some of this good cave diving. I wasn't too excited about it when I started, but I'm an addict now. New holes keep springing up and that's always nice.
Georgitsis doesn't teach any penetrations up there?

Cheers

[Uncle Pug]

Divesherpa once bubbled...
Come on down here, Pug, and do some of this good cave diving.
It is on the list... that and the Great Lakes.

[Divesherpa]

I'm a firm believer that caves are far safer than wrecks, but wrecks are far safer after cave training!:D

Don't put it off too long, the class costs are rising. If you need someone to help with planning a course, let me know.

[MikeFerrara]

Divesherpa once bubbled...
I'm a firm believer that caves are far safer than wrecks, but wrecks are far safer after cave training!:D



I will second and third that statement. I've seen some ugly stuff in wrecks. And then there is the fickle sea to deal with. But I love both anyway.

[Mo2vation]

Looking at Bottom timers... pouring through posts. "RT" keeps being referred to. I don't want to guess...please 'splain.

Thanks -

Still lurking - real questions to follow later.

k

[trymixdiver]

RT = run time

Andy

[MechDiver]

Mo2vation once bubbled...
Looking at Bottom timers... pouring through posts. "RT" keeps being referred to. I don't want to guess...please 'splain.

Thanks -

Still lurking - real questions to follow later.

k

Rt is RunTime. It is time that accumulates as the dive progresses, starts when you descend and ends when you surface.
For a typical profile, instead of saying we spend 3 minutes at 50', we get there at RT 60 and leave at RT 63.

MD